A few months ago I bought the keyboard for an S8- And now I bought the phablet for it!
There are MYRIADS of reviews of the S8- and S8+ out there, e.g. here, so this is not my main focus here, but the total experience with the keyboard.
I have been on the lookout for a replacement for my BB Priv for a while, and had my hopes up high for Livermoriumltd.co.uk project of a Mod for the Moto Z series.
But this project has unfortunately been cancelled.
A new project is close to going public (expected in October), that should give us real landscape slider phone. 
But as this is not going to give my the device in my hands for the next half a year, I looked for an intermediate solution….
I accidentally stumbled on the S8- at a friend last weekend, and it was a really appealing device. Unfortunately I did not bring the keyboard. So took the chance and bought one.
The S8- with a click on keyboard is actually a really good compromise in lack of a slider. When the keyboard is not attached you have a device in a protective case that looks and works like any other modern slab. (with two tiny notches at the side no one will notice)
And the keyboard part (less than 20g) slips easily into the shirt pocket.
They even offer the ability to click it on the back. I do not think that I’m going to use that much. But perhaps in the summer with shorts and no shirt pockets it might become handy. No matter what, it is nice and thought through, that they give us the extra ‘storage’ option. ADD: Actually the option is rather handy in bed also.
ADD II
They have actually thought more carefully than you might think at first about where the two side notches are…
One of them perfectly matches the cut-out for the power button, so you can also store the keyboard clicked on the top back to protect the camera and fingerprint reader!!
Sure as it also protects the fingerprint reader, it is most suited for transportation (or if you use iris authentication, or other options only).
As a bonus that particular placement also gives a nice slant, when the device is placed on a table.
(Though it is not so smart that it detects the placement and turns off the fingerprint system and switches to front camera only)
For more on the keyboard technically, including a disassembled one, see here.
Aeroplane mode and NFC
Oddly the keyboard ALSO works both in Aeroplane mode and with NFC turned off, so the communication with the case must be a dedicated circuitry.
Overall
The whole experience is that it works absolutely flawless as you would expect when used with English input & prediction language.
Some reviews complains about the unusual long 18½:9 aspect ratio of the S8-, but the elongated device is actually a benefit in this constellation as the display with the keyboard ‘only’ goes down to 13:9, and that is not terribly far from a standard 16:9 slab.
Note that you get a MUCH larger remaining area during input with the physical keyboard:
On the home screen they squeeze the grid-cell size, and crops top and bottom of the wall paper
The grid layouts 4×4, 4×6 and 5×5 all works fine, but there is an odd bug that 5×6 ends as 4×6 hiding the last column – but as they can handle both 5 columns and 6 rows just fine, this must simply be a mapping-bug somewhere – unlikely to be corrected though, as it is still there a year after release… ADD 2019-01-07, 5×6 now also works, I stand corrected, they have fixed it silently along with one of the security updates.
Differences with or without the keyboard attached, and a tiny issue with workaround
The only TINY issue I’ve experienced this far, is with an app the usually replaces the software keyboard area on the screen with other input options.
I saw it in Textra (SMS/MMS app), but I will expect other apps that replace the keyboard (temporarily) could have similar issues.
In Textra when you want to add something (emoticons, media…) you can press “+” next to the text entry, and it is supposed to replace the virtual keyboard area with a content selection area. Here is how it looks without the keyboard attached
With the keyboard the + fails, unless you press Alt-Sym on the keyboard first, to show the Samsung keyboard emoticons system, and then the Textra + will overrule that…
With the Alt+Sym pressed you get the middle above – and of course you can take emoticons from that directly. If you THEN press the + you get Textra’s options.
If you do not press the Alt+Sym you will get this (note the + replaced by an x), but nothing becomes available
Without the keyboard you -of course- get a much larger pure reading area, a smaller area during input, and a more spaced window for adding content, as the virtual keyboard is replaced rather than supplemented with emoticons or attachment selection…. Pros and cons…
Key-layouts, special chars
It is bad for the learning curve that the alternative characters are NOT at the same letters on Samsungs virtual and physical keyboard…. (e.g. a dash on the Z on the virtual keyboard and on the I of the physical) Actually not even a single one is placed at the same letter!!
It would have been clever if they offered an optional virtual layout matching the physical. That would have helped learning the positions quicker, and this is more important than other keyboards due to the the lack of backlight….
Screen zoom
Note that I in the phablets Settings, Display, Font and screen zoom have selected the “Screen zoom” to Large, and a small font.
Had I chosen medium or even small zoom, it would all look less cramped (and the virtual keyboard 3-6% less of the display height – and slightly less space between the key-rows).
Here is how it looks with Small zoom (same font size)
So if your eyes and fingers are up to see/operate that, it will of course give you more available content on the display.
If I do not select Large, It is hard for me to distinguish some emoticons, so I need to pull myself together and get new glasses. But in the meantime: Large zoom….
Oddities
- Auto rotation is disabled, forced portrait (Can be overruled by third party apps though) – But Portrait make a lot of sense while clicked on… (The icon in notifications confusingly stays as Auto – ought to be greyed out)
- Some apps get confused if you click the keyboard on/off inside the app (e.g. QuickPic), but if you close and reopen it works fine. For some apps clicking it on while in Landscape mode could do the trick, as clicking the keyboard on goes to portrait, and thus requests a complete redraw.
- When attached, the Samsung Camera app ignores the chosen picture aspect ratio and forces it to 1:1. It is fine that it (like Full Screen mode without the keyboard) defaults the aspect ratio – but they should allow me to override it to use the full 4:3 sensor, and not force crop!!!!
- Using an extra (tempered glass) protector on top of the film mounted from Samsung, reduces the sensitivity of the keyboard add-on, so I might remove it again…
Avoid using the home screen in 5×6 mode (see above)Fixed!
Lack of backlight
If you are in an ill lid environment the lacking keyboard back-light is tiresome. But no more than you can just click the keyboard off and use the plain touch keyboard in these conditions – and anyway after a short period of usage, you are likely to be able to use it without looking (I’m not there – yet). So not a big issue.
National letters
My main worry was the national Danish letters æøå and indeed the software handling this is MUCH less thought trough than the BB Keyboard app… 
It IS possible to enter them as individual letters, but it does not interact well with the text-prediction.
You have to long-tap K/L/P to get national æ/ø/å (or select among accented letters A/O/A), BUT it incorrectly sees this as ending the word! And sees the rest of the word you type as a new word where auto-correct can make havoc in the total word…)
If the national letters are beyond the two/three first letters, there is a high chance that the predictive system correctly suggest the words. But if it is letter number one or two it is cumbersome, and we got quite a few small words in Danish.
After quite some experimenting I found a workaround.
Let us suppose I want to write “Sea lion” that is “Søløve” in Danish, I could do the following
Tap “S”,
long-tap “l”, tap any letter (e.g. the “i”) and a space, followed by two backspaces (this re-enables the prediction system!!)
tap “l”,
long-tap “l”, tap any letter and a space, followed by two backspaces,
tap “v”,”e”
…So we need a long-tap and four normal taps for each national or accented letter…
Bonus: No Bixby!
And as a welcomed bonus, when the keyboard is attached you will not be pestered by Bixby
YES I know you can disable the button temporarily BUT only after letting it upgrade Bixby, connect to Samsung with a Samsung account first 👿 And sure you can remove the account afterwards, block access from Bixby junk in the NoRoot VPN firewall, and stop all the Bixby-junk (Do NOT downgrade “Bixby Home”. The other five can be downgraded/disabled and stopped, after the button is disabled – If you downgrade Home too, the key is re-enabled…). And even if you do all that, after a restart you will need to do all this account fiddling again.
…It is not unlikely that I will find a way to mechanically block the button, e.g. a strategically drop of cyano crystal….
Add: More bloat clean-up
I found out that I can do more clean-up than just the usually uninstall and disable of apps allows for.
See this. This method allowed me to ditch Bixby completely.
General S8- stuff and conclusion
Overall the whole experience of the device (and keyboard) is really good! 😀
With the case it is a whole 10mm less wide than my Priv with a case, and thinner. So it is MUCH easier to operate all the screen with one hand while keeping a reasonably secure grip, than on the Priv – where it is impossible (for me). With the S8- it is not super easy, but not entirely impossible either.
To my great surprise actually ALL the keys of the physical keyboard can be reached with the thumb when one hand operated!! 
What at first looks like waste-space at the bottom ‘corners’, are actually crucial for one handed keyboard operation, as your thumb can ‘lean over’ without pressing any keys!!
So the S8- is a phablet very close to could be called a phone 😀
The camera does a quite good job in good light, and has a nice fast lens for poor light (considering the lens size). All other modes than 4:3 is cropped from this.
the ‘zoom’ actually does a little more than just crop and stretch. I assume that they apply less image compression. BUT if I e.g. ‘zoom’ in by a factor 8, it gives me an image with a size of about 2MB, but the quality is close to VGA or XGA… so pretty absurd.
Here are two pictures taken in moonlight ONLY, with everything on Auto:
Of course they are far from good, but considering the size of the lens, and a 8mm thick device, not that bad even at 1/4 s
Here is how the same looks after an auto-adjust in IrfanView. A lot of noise, but the motive is there, even with a shadow…
Here a daylight picture of the same motive, and it does a nice job here too.
It does quite good macros for a mobile as well, here taken a cloudy last day of September. Click to enlarge (Yes WP handles rotation of displaying some reduced portrait images wrong)
The above are without crop and stretch (aka digital zoom).
Note that the S8 have a bug in the EXIF info on the ‘digitally zoomed’ images, as there is no way to see the crop factor in the standard EXIF.
Though you CAN see that some ‘digital zoom’ have been used as two tags are present on the full image only.
Here from my PhotoView that can display more EXIF than most.
● Shutter by apex (1/2^5.64)s
● Aperture by apex F √2^1.53