The only thing you have to remember is that it's still work in progress. Compared to ICS though, it's a lot better battery wise. I can't really give you an estimate because I fell asleep the first night trying to run the battery down by just using it (it was like 4AM though and I fell asleep at like 7), but the standby is pretty good too.
It won't tell you if it's charging either, but that's because we don't have the updates for the firmware that would let us see that. The light works though, and will change to green when it's fully charged.
But it is so worth the saving of $200. Some of the XDA people are kinda iffy about their pre-orders now because it works so well.