Don't get me wrong, I like my g403 just as much as the next guy, but that's not to say it's definitively THE mouse to get.
IMO the most important thing is just that it fits your hand/grip style well.
If you can't hold it in your hand comfortably, it's a no-go, even if it's got the best sensor or scroll wheel or wireless technology.
The price is obviously a huge factor but I haven't found the battery life to be an issue at all. I just leave it plugged into the USB charger overnight or during classes. It's not like you need to be using it 24x7 or stockpiling AA batteries lol.