I never really complained, but longer battery life would be much welcomed! It's not that bad unless you use it often all day long, or access the Net on the cellular network for a while. It DOES recharge pretty quickly, though. Mine doesn't even have 3G, which is supposed to be a bit faster (so I welcome that), but WiFi is still the fasted. But yeah, the 3GS has a faster processor that should speed most everything up on the phone itself.

This update is nice if you're upgrading from the 1st Gen like I will be. It's not a "major" update from last year's 3G model (although the new OS 3.0 IS fairly major, and available for all models)...