I dabbled with Dvorak years ago, and gave up in frustration before I got very far. I stayed qwerty for years until discovering Colemak, and I'm currently a few weeks into my switch. I think it is WAY easier to learn than Dvorak. Because there are so many of the same keys as qwerty, and because the punctuation doesn't change, and because the layout feels intuitive (common letters in easy to reach places), I learned the layout almost right away.
After 2-3 weeks I'm at 20wpm (I'm 60 in qwerty), but it still takes some concentration (I can't write anything that takes much brain power because I need to anticipate each key press), and I still have some problem keys.
I code too, and re-learning things like 'ls -l' and 'cd' and 'pwd' seems to take another effort at retraining my brain, as my practice with typing text in Colemak doesn't seem to have helped my command line muscle memory!
All in all, I'm happy with Colemak. Take note that some coders reject Dvorak purely on the basis of the awkward placement of the 'l' and difficulty in typing 'ls -l', and I think they might have a point.