The high limit players can spot possible collusion and would have your play investigated so fast it would make your head spin.
So it's not too uncommon a thing to happen?!

Consider the amount of time spent comminicating. Why not use that time to play on more tables? I can't imagine colluding on more than 4 tables at once. Collusion would increase your short term profits but I don't think they would double. You would be better off 8 tabling and playing straight up than 4 tabling and colluding. Unless you don't have the skill to beat the game straight up.
I have to agree here.. I don't see any long term benefit. "Maybe" play a bit more profitable on one table as opposed to playing more tables at once, lol..