I see these same names mentioned a lot. The fact that they are mentioned a lot and get mostly good reviews leads me to believe they are good.
However, I have to think there are more than the 5-6 surgeons that are always mentioned that are good. I guess if you're on a site like this, you go to the surgeon everyone recommends and then you post about your results. If you're not on a site like this, you go to another surgeon, may get good or bad results, and don't post about it.
So I guess the safest thing to do is to go to one of those 5-6 surgeons because you know they're good. But if you'd rather not travel, or don't have the money, you may still be able to get a good hair transplant by a lesser known surgeon. Anyway, that's what I'm thinking, though I may end up going with one of the famous ones in the end.