Ok so i just got the mophie juice pack air for xmas. Heres my review. The design is perfect. Its sleek and feels sturdy an well constructed. I have an otterbox defender as well and the mophie is slightly slimmer than that. It gives good access to the power, audio port, and volume buttons. I love the led battery meter on the bottom. It comes with a usb power cord than can not only charge the case and the phone but sync it to itunes as well. The cord however is pretty short so that kinda sucks. The charge from the case is just enough that if you completely let your phone drain, the case will charge it back to full once and thats it. I do have one complaint and although it is a very big problem, i dont think it will happen to all cases. But there is a switch on the bottom left side that turns the charging on and off. For one the switch seems flimsy and cheap but when i turn it on my phone will make the charging noise but then if i barely move the phone it will lose connection on and off. The case is on snug so its not that so i think theres some loose wires inside the case. I plan on exchanging it but still. Hopefully its not a common problem. Overall i still love the case.