Lets start with my first impression of the Juice Pack Air. Holding the case in hand, you will immediately notice the premium soft touch finish of the case; it is REALLY nice. The next thing I noticed is that they have finally moved the status LED's to the back of the case versus having them on the bottom. In addition to that, when the case is being charged, the lights will illuminate for 30 seconds but will turn off after that as to avoid being bothersome when you have this charging on your nightstand at night. The last major thing I noticed is that the charging port has moved to the bottom instead of the side which should help out a lot with broken ports like the prior cases. Speaking of the charging port at the bottom, it looks like there are gold contact patches - could this mean some sort of Mophie dock?
As for the technical specs, it packs a 1700 mAh battery which is touted to provide up to a 100% charge of your device. This will vary of course based on your usage while it is charging along with your phones settings i.e. email push etc. This amount of power should suffice for most users without a doubt. One thing to note is that you cannot sync your phone over the provided wire. You will have to sync wirelessly to iTunes. This should be a non issue for most people especially since most users sync to iCloud over night anyways.
So, with all that being said, I love the Juice Pack Air case and certainly recommend it. You simply cannot go wrong with a Mophie product. The Juice Pack Air case retails for $99.95 and is available in 3 colors - Black, White and Red.