Haven't played much at 10/20 yet, but so far the tables are just as loose, if not often looser, but the play is more aggressive. I have to really watch my post flop play walking the line between making good folds and avoiding being pushed off a hand. The 45/25/3 types are reasonably common.

I've found so far the 10/20 players just don't care if they lose the money. At 5/10 I found more weak-tight amateur dabblers. At 10/20 the players seems to be just financially well off and don't care if they blow $2000 in a night and consequently play fearless.