After the release of the Mophie Juice Pack Air for iPhone 4 last year, Engadget posted an excellent side by side review of the Mophie JPA and the Mili PowerSpring.

“What was compared?”

Besides the obvious specs & performance, comparisons were also drawn on design – aesthetically & technically (ie cut-outs for iPhone functions), packaging (Apple fans are fussy!).

How’d they Stack Up?

First Impression – Mili won for their packaging which is slightly more compact, economical, and consistent with Apple’s own products. However, the Mophie is still a clean and stylish packaging design, with lots of information on show.

Size – If that’s important to you, than the Mili is slightly shorter but is also slightly wider and thicker than the Mophie.

Comparable performance – “Was there a winner? No, not in terms of raw battery performance.” They are comparable in performance and whilst neither double your iPhone time, they do generously extend it. Although interesting to note that considering the Mili is 1600mAh and the Mophie 1500mAh, Mili doesn’t out-perform the Mophie.

Overall winner?

Engadget agrees that Mophie wins overall

…With the batteries being equal, choosing the winner comes down to price and design. To us, the Mophie Juice Pack Air’s superior build and flexible, two-piece design more than offsets the $10 premium it currently demands.”

But we’ll leave it with you to make your own mind up. Read full review here: Engadget

“Where to Buy the Mophie Juice Packs?”

For iPhone 4, we have the award winning Mophie Juice Pack Air (1500mAh), as well as the Mophie Juice Pack Plus (2000mAh) for super users.