To add onto what Earlymon just said, I posted this in the review thread:
From that PC Mag Review
Battery life is an interesting poser here. The EVO 3D gets eight hours of talk time, which is great. But heavy 3D or 4G use will kill the 1730 mAh battery; if I left 4G on, or took a lot of 3D videos, the phone could be dead after about 12 hours of use."
I for one do not leave 4G on all day at work, so I'm assuredly going to get more than 12 hours. And im pretty damn sure I will not be taking 3D videos at work.
Considering, with my EVO, my 9+ hour work day, it truly depends on the day as to what my EVO's battery will be at.
I can tend to be a heavy text user while at work, medium web browser...and I have my work email pushed to my phone. It varies on the day and usage.
Some days I can leave work and my battery be at 70%, some days at 30%. Truly depends on what you are doing that day.
As long as the 3D can beat that...and by that PC Mag post, it looks like it can...Im a sure deal of getting the 3D.