Weirded out owner of the first convergence device here.
I bought a bluetooth keyboard and mouse the day the tablet showed up in the mail. The tablet is engineered to be used that way, right? Pairing, check, desktop mode, check. Open some webpage to see how everything works. "Please enter email address and password" (I must have been on facebook or something)... Epic fail: I can't type the character "@".
On a standard German layout, the "@" sign is reached with the combination of "alt gr" and "Q". There are plenty of characters that can only be reached through "alt gr": "{ ,[ ,\, ~, |".
Since then, I also found out that none of the dead keys work. To make a "ê", I'd type "^" then "e". Typing "^" doesn't do anything. Typing "e" afterwise does a regular "e". Same with every other accents and non-ascii characters that the non-anglosaxon world absolutely needs to communicate. I mean, I started writing an email in French to my mom and stopped after a while and finger-typed it on the screen, because the unaccented version didn't make any sense.
I could spend a few hours remapping the keyboard, but the "keyboards" utility we've all been enjoying since the night of the age doesn't seem to exist in Ubuntu Touch, and has been replaced with a 3-options-menu.
Before you mention it, that 3-options menu doesn't let you pick a "compose" key. And, while we're at it, I did select the correct keyboard layout. All keys produce the expected character, except the dead keys and the ones that require "alt gr".
The keyboard itself is not at fault. I paired it with an android device, and it works as expected. I'm even typing with it right now! @ é è € {[]}