That's fantastic for you but I think you might be on the wrong forum. We're talking about the G1 here.
I leave off 3G, GPS, and all the extra slack that isn't needed. I've recovered tons of battery life saving tips from across the internet and STILL my battery life is about an hour or two when I'm playing with my phone. Consistent usage, mind you. My battery was fully charged last night and I figured if I didn't use it one bit, it wouldn't die. Seriously misinformed. I woke up and it was completely dead.
I haven't got the update yet which is supposedly supposed to help the battery life. Perhaps I'll report back once I get the update. I remain optimistic despite the short-comings of this phone thus far.
On-topic: The difference in milliampere's isn't enough to really make a lasting difference. I mean, sure, it'll give you maybe an extra 45 minutes but if you carry around your wall charger and invest in a car charger then you'll be fine. No need to shell out so much money for a third-party battery.