Uh... it's sort of all over the place. Half the people score better, half score worse?
I personally scored almost exactly what I thought I'd get on every section, but I also had a lot of friends who did much worse then they thought they would.
In general, I think it is rather comparable... But that is VERY general. Like, you will likely end up plus or minus 3 points from your average test scores.
Again, most people also end up with a wide range on their practice AAMCs. If you're going anywhere from 28 to 38, then it's hard to really predict your scores. My practice test range was within 2 points for 8 practice FLs, and I did exactly in that range.