Hi!
I have made the switch to the Colemak layout on a whim a few years ago, I think it was three already. The wierd thing is that I don't notice myself using Colemak at all, and it never crosses my mind that people use another keyboard layout altogether, so it is always a bit funny when someone attemps to type something on my laptop!
Using Colemak is great, I never have to install anything, as my desktop is an Arch Linux installation and my Laptop is running Mountain Lion. Both OSes have included Colemak since forever.
My reason for learning the layout was to learn touch typing at the same time, and it worked very well. In fact, I can only touch type; if you ask me where a particular key is on the keyboard I will have to stop and think about it for a while before knowing for sure. My fingers have learned the layout as a "relative" system, keys are located near the home row position and that is how I can type. With QWERTY I was a hunt-and-peck-er.
My accuracy is not all that great, but I think a mechanical keyboard would go a long way toward solving that.
take care