I have one and they are fabulous. I’d go to sleep at 100% charged and wake up at 5% charged. My phone is my alarm clock so this occurrence made me worry… With this attached battery, it will stay at 100% for a couple days.
I have a number of these, which I think are better deals than yesterday’s $35 “plus” model.
Only minuses:
(1) The top part’s sides have teeny tabs to hold them tucked into the bottom part. These will break, guaranteed. This means the top’s sides will pop out a bit on the sides (about 1mm or less). Not a big deal.
(2) The charging LEDs on the back are VERY bright - disturbingly so, if you charge the phone by your bed. Solution? Electrical tape.
Big plusses:
(1) The battery works great. Easily doubles use times.
(2) The case is reasonably protective and doesn’t mess up photos too much when you use flash (or you can just take the top off).
(3) It charges with a microUSB cable (included), which means you’re more likely to be able to use the same charging cable as other devices you own.
I like mine too. Even under heavy use it can easily double the battery charge. I love that it changes the connector to a more-compatible micro usb too. The only downside is it can take forever to recharge fully.
Bonus of having the Woot Off going on at work: convincing the guy sitting next to me that he needs a(n) [uNu iPhone Case] so the next item shows up faster.