Battery life is great on v6 but I'm having a lot of issues. So far I've had my phone reboot 10 times in the past three days over little things.
Pressing and holding on an app to remove it from a home screen makes it reboot if the phone has been running for aver an hour.
Using a live background makes the phone reboot within 3 hours and the background is no longer there (being replaced by the wallpaper I used before)
and the ics clock widget that comes with the theme gets stuck once or twice a day requiring a reboot to fix.
General issues:
The background no longer scrolls with the home screens like it did in v5.2.
I cannot go into landscape mode without the wallpaper being put into a weird aspect ratio, I think 4:3 instead of 16:9 like it should. (just thinking of normal non-widescreen and wide screen, I'm not sure if the aspect ratios are the same for phones)
the battery life however is simply amazing. 15 hours of use yesterday (light use) and it was at 56% battery life. I'm going to flash the rom again and see if that fixes these problems because no one else seems to be having them.