I had PRK done on one eye, and Lasik done on the other. My doctor was not comfortable doing lasik on one of my eyes and said the PRK eye didn't have enough tissue to cut the flap and leave enough "wiggle" room to do any corrections in the future. I had both eyes done at the same time. The kicker is, my PRK eye turned out better than the Lasik eye, and is more comfortable. (Note: Only had it done 6 months ago, and am still getting used to it). The recovery and pain sucked though on my PRK eye. It was swollen shut for 2 days, and then took a week to look normal again, although I could see perfectly with that eye the whole time. My Lasik eye on the other hand had no pain afterwards, but is less comfortable now (ie: I can tell something was done to it, but not painful).
Given the choice again, I probably would have PRK done on both eyes, just not at the same time.