From my limited experience, the $20s are actually easier than the $10s. More "plays" so to speak, which just ultimately mean bigger pots and faster eliminations. It's great for the tight player who is very conservative in the first 3 rounds like myself. I have heard, however, that there is a noticable jump in skill level from the $20s to the $30s. I'll find out.
I will post more updates as I play more of the tournaments.