The standard recommendation is to type Sholes 5-10 minutes a day to maintain your ability to hurt your wrists. I haven't bothered to do that and it's a good thing I leave my keycaps alone for the few times I run a VM that is stuck in US layout. I've lost the rolls and fingerings as I've gained them with Colemak.
It's really sad when I have to use someone else's computer, but then I remember that my emails were never longer than a tweet when I first started with Colemak.
I can use it, but I can't touchtype it, so I do feel a little stupid sometimes typing on qwerty and probably couldn't do it without at least glancing at my hands. Its worth it for me though because I spend so much more typing on my own colemak keyboard than I type on qwerty.
