I bought 4 extra batteries (generic) and did have one completely go bad (It reads "Battery Not Supported" in camera even though it previously worked, and I still am on 1.1 firmware) but I would say they all run longer than the OEM battery. Add in that lots of the "OEM" batteries on eBay are fake, I will still to the $12 for the generics and just toss them after a dozen or two shows. Bring lots, and two 16GB cards.
I wish they could fix the focus and the striping issues and it would be perfect. But I will keep using mine for some time. I really like it, and it's got great sound.
Too bad we can't embed videos on here.