I had a 4S that had been heavily used since December replaced under AppleCare+ for water damage. Was told at Apple Store that, yes, the motherboard may be a reused one, but that camera and battery were brand new. I also have an iPhone 4 that, since I bought the 4S, was provided to me by my job. This reaffirms it. The 4S battery life -- even when the battery is new -- is just god-awful. Shockingly bad.