I don't have any experience (yet) with the green, but that will be changing soon. I have owned 5 CT (red) lasers, and someone at CT's sales/marketing is on the ball--just Thursday afternoon they sent me a nice, big full color catalogue.
I've been waiting for CT to come out with a "proper", grip-mounted green laser like their red ones for 1911s and S&W revolvers. Care to guess what is in their new catalogue?
unfortunately they cost so much for a green one...
Not any more. The new CT ones are $399 MSRP, which is only ~$30-40 more than the red ones.
Now as far as battery life, that appears to be true. CT says 4 hours life on a red one, and 2 hours for the equivalent (same grip, same batteries) in green.