There's no answer to that.
The more hands, the closer to expectation you get.
It is true at higher variance games that it is more likely you will run far below or far above expectation, but that doesn't mean you should dismiss expected return as theoretical mumbo jumbo.
I can respect the argument to stay away from high variance games. In fact, I now do that myself for the most part.
However, I cannot accept the argument that a 7-5 game isn't vastly inferior to the equivalent 8-5 game, simply because "you are going to win or lose based upon the big hands".
Every time you hit a full house on a 7-5 game, the casino is literally stealing 5 credits out of your pocket that you should have had.
Let's say I sat next to Rob when he played a $5/credit 8-5 game and demanded he hand me $25 every time he hit a full house. He would feel the pain of that each time he hit the full house. If Rob hit 8 full houses during his session, and I showed him the $200 he gave me, I bet he'd be pissed and feel like I took advantage of him. However, he seems to have no problem simply playing a 7-5 game. Since there's not a person physically grabbing $25 from him on each full house, he doesn't truly feel what a mistake he's making.