I've always wondered about that AccuKey though.
Chording is a nice idea, could be brilliant if wrapped around the edge of a phone/PDA (e.g. http://www.xaphoon.com/dataegg/ ) but is too slow to be an everyday desktop keyboard replacement. Less comfortable than normal typing, as you use many fingers per character instead of just one. Even if you're one handed it's probably still faster to type on a normal keyboard.
As the CyKey goes, it has a bit of a classic Spectrum rubber keyboard feel, not much feedback.
Don't splash out just to try the idea, I've just cobbled together some Python/TKinter that you can play with here:
It's a text box and you can chord using the right arrow key along with the numeric keypad keys 4/6/8/enter (I find them a pretty good fit for my fingers).
The chords are here: http://megasharp.com/cykey.asp (plus "thumb" on its own for space).
There are many more in the CyKey system for numbers, punctuation, shifting, control keys and so on, but a) I don't know what they are, and b) it's freaking patented/copyrighted so I oughtn't even use these few.