I purchased one a few weeks ago. They do the job well. The only downside I see to it is that you can't leave it in pandora mode. The lights flash when it's in service mode. They continue to flash while you use it in service mode. Not a big deal, but it'd be nice if you could leave it in service mode and then bring it out and make it standard again.
Works great though. The button on mine is a little hard to hold at times, there's enough resistance that it feels as if you're pushing but sometimes you're not really pushing. If that makes any sense at all. I don't see this as being a flaw though. The build quality is good, feels like a stock battery. I don't really notice any extra bulk either.
I have yet to test out the full life of the battery.