Any one got one of these babies before I take the plunge and replace my stock radio/cd?

Unfortunately I did not put this unit in myself (Car Toys did, and they did a great job). I did have to remove all of the dash components to move a USB port to the glove box after the fact and I have to say pulling the dash trim pieces apart in a 4th gen T4R is easy. My antenna is actually mounted on the roof (magnet) next to the Sirius XM antenna just above the rear hatch behind the high center brake light. I did install the GPS unit in my previous car and I mounted it on a frame pieces inside the dash behind the head unit and never had any problems. I'm sure you could do the same before trying to fish the wiring around the headliner.
.. which is why I didn't get the backup camera. By the time the unit powers on I am normally already moving forward.
How does the wire from the roof get inside the vehicle?
The antennas are at the very back of the truck in the center. The wires are tucked into the gap between the hatch and the truck itself. (maybe an inch of wire total of which you don't see) and then it goes into the truck by the weather molding. It's the same setup the dealer or port uses when they install the XM module for the Urban Runner's Tom Tom (at least in my case anyway).