700u does have usb connectivity. there's 2 cables behind the flipdown door. one is an ipod/iphone cable and the other is usb for thumbdrives. no cd tho, so you have to be ready to ditch that. had I known that the 700u did not work with the old kenwood remotes, I probably would have researched other decks from clarion/alpine, but was originally lead to believe that they would work based on crutchfield's website. didn't find out until I was wiring the deck that they won't work. so had to pop the $100 for the new remote..
am more than happy with the 700u, but I am betting I would also be happy with alpine as well.. really, both are excellent choices.