from what I've played around with they are a pretty good deck as per usual from Pioneer.
The built in bluetooth is terrific in the full 7" screen compared to the 5.8" with the 3300BT last year. The add on module always sucked, never transferred phone-book, and a few other things.
The ONLY thing I don't enjoy about the 4400 is the actual interface looks very pixelated. Other than that, I think you'll enjoy it!