Normal Rake vs. Time, winrate question

[brinks]

I am a semi-regular player at the Taj, usually playing 2-5nl or 5-10LH. This weekend was the first time i decided to play 10-20LH, as i finally decided that i had the roll to do so.

The question is: At 5-10 the rake is still max 4 dollars per pot, while 10-20 is 5 dollars a halfhour. I played for roughly 30 hours= $300/15BB. Being a TAG, playing fairly few pots, could this move from 5-10 to 10-20 be significantly affecting overall win rates, so much so that 5-10 may be a better game to play in? Thinking in terms of hourly rate alone, not relative ease of game.

And if so... whats my next move up? 15-30, 20-40? that move might be a bit of a shock