Which is better: Mili vs. Mophie vs. Exogear vs. Energizer ?

[lucil]

i stumble upon a summary review about 3 different battery cases.
morphie vs. incase vs. Splash O2

ehkia.com | iPhone 4 Battery Case Comparison, Summary & Review

 

[Bluering]

The convenience and the peace of mind to know that you will never run out of power and you don’t have to carry another accessory or a second battery in your pocket just negates the slight bulk and at the same time it is a case that protects your baby and you get to use the more common and popular micro usb connection.

 

[PDADoc]

Just bought the Morphie Juice Pack Air today, I don't intend on using it as a full-time case, though. I'll carry it in my briefcase and use it as I need to.