Hi, just to add another happy conversion story to the (already long) list..
I am a German that mostly types English and programs and switched four months ago. My typing skills before were always up-and-down as the QUERTZ layout makes programming quite painful. Brackets, backslash etc are all only available through AltGr, which meant that longer programming periods would quickly move me away from touch typing.
I considered switching to QUERTY but instead went for Colemak and am now a happy camper. I have not measured my word rate, but my touch typing is now effortless and certainly the same speed as before with QUERTZ.
My OS is Ubuntu Linux on the laptop where Colemak is offered by default. The layout on Ubuntu has one bug I have not fixed yet though- the caps lock key works as as backspace, but still activates caps lock.
Recently, most of my typing is moved to a Nokia N810 internet tablet (running Linux) with a tiny IGO stowaway bluetooth keyboard. After a bit of fiddling I am using Colemak there, too. Works just fine, the bluetooth keyboard sometimes duplicates characters though, but that's a hardware bug.
So overall, I am very happy with this layout, especially as it works well for different languages and programming. I have some long typing ahead for university, that should help to further refine my skills..
Kind regards
Gabriel
PS: I went cold-turkey right away, with a printout of the layout next to the laptop on the first day.. It was indeed quite frustrating at first, but after two weeks or so that was gone. Probably not being a perfect touch-typist before helped :)