I usually run SL on "mid-class" hardware, that is normally powered computers with decent, but not top-of-the-line graphics cards. This weekend I got the opportunity to test SL on a friends "gamer computer" (he's a WoW addict, LOL), and that was a real eye-opening experience. Walking around the world with graphics all set on max, and still have 30fps, the Apollo Sims looked even more beautiful than I can remember them.
Still, things took a long time to rez, but I guess it's just that loading every prim within 512m range takes a while, even with the 1Mb network speed I got on the server connection.
The images are high-rez, click on them to view the full detail.