Well, I did a little look with the detailed round viewer (which I didn't even know was there before) to compare some of my rounds to aspirin's (just because he is top atm, and is on FA#2 exclusively).

He doesn't have much info, but taking it from his and my last 5 rated rounds the average rate across all prated players in rounds is pretty much identical; 9.556 for asp and 9.554 for me, which I found surprising. However the average PPM across all players in the rounds was 8.1 for me but only 6.442 for him i.e. the average ppm of players I play with is 25.7% higher than aspirin. Meaning the players I am playing with are in the long term, as good as those Aspirin is playing, but in the actual rounds I play against them on Jay#3, they do better.

Now you could say that Aspirin is a good player, so does so well he keeps other players rate down better than I. Well, that doesn't make sense, since you would expect his ppm to be much higher, and often, but its not. So, if thats not it then another factor is making players of similar rate to which I play, do worse on FA#2. Now, I don't want to sound like a douche here, but the only factor that I know effects almost everyone apart (aspirin being in that select few) from a select few on Jay#2 is the lag. It is certainly probable that if you are not lagging, you have an unfair advantage over laggers. Likewise, better players are also probably better able to cope with lag even if they do have it, adding another way in which they are more skilled than the average player.

If you can think of anything else that could cause this difference in ppm, go ahead. However, to me it looks like perhaps your ping in relation to average ping should be taken into account.