i can vouch for the 3500 battery. Bought it and have been using it. I figured the most accurate way to measure the battery life would be to leave it unplugged and just not touch the damn thing since saying i used it for 12 hours with moderate usage is rather subjective....
To my surprise, it discharges at a rate of about 1% an hour if not doing anything on it! On stock, running CM7, it would discharge at a rate of about 5-7% (i did used to have better battery life on the stock battery with netarchy's kernal and myn's rls 5 but i love gingerbread too much and realized i don't need sense [fyi it used to discharge around 3% if phone left on with wifi enabled and not doing anything) My results are better than expected because I did also apply the "lower havs -75mv havs edit" by viper in the development thread.
So in conclusion
3500 battery + savage-zen kernal + CM7 + vipers HAVS edit = awesome battery life
FYI: I did have to charge the battery fully and reboot once it reached a hundred to actually fully charge the battery. When I got it, it charged at a rate of about 5% per minute which I thought was really fast. Once it hit 100% I rebooted, it went down to 87% and slowly charged up to 100% (over 20-25 minutes). Then from there, I got awesome battery life.
I also tried to charge the battery with the phone off at that point and it didn't continue to charge; I also plugged the battery into an external charger at that point and it didnt resume charging either so I figured it reached full capacity.