The play doesn't really vary too much from 0.50/1.00 to any stake on most sites.
I've always wondered why this is...
I think its generally because, at higher stakes - people have more money to play around with and lose. You also bump into some pure gamblers looking for a big win.
On some sites, the smaller ones mainly. There is a big difference as you move up stakes.
However on the larger sites like Poker Stars
and Full Tilt, you can often find a game that suits your type of play at almost any level. Be it Super tight or loose crazy.