I have to say: I do notice when I’m stuck on the 2(.5)G network for a while the page load times are atrocious, compared to 3G. But that 3G network is certainly thirsty.
I’ve seen a lot of whinging in the blogosphere about how bad the battery life is, and I’m also not overjoyed by it when I set the GPS going with 3G and put some good tunes on over the speaker in the background — but there is an easy alternative. Don’t use 3G, or the GPS and use your headphones and you’ll find that the battery life improves dramatically. Heck, try turning on flight mode so that the radio is never even on and the battery goes on and on and on.
Why, you might reasonably ask, would you every turn off the radio and never use the network? I have found that my number one app on the iPhone is the NetNewsWire news reader. Online, you can choose which feeds you want to read on your iPhone and will sync up your feeds (and clippings), download them all in one session so that you read them offline whenever you need to. During my holiday whilst I was maintaining a data roaming blackout and the Portugal Telecom wifi was tedious to log into, I synced up every day or so and read more on the iPhone than I generally do on my Mac at home or my PC at work.