I use the Thule (T2 XTR) rack shown in other pics in this thread. I like the basic style of the rack; however, I am not a fan of the clamps used to clamp the tubing the bikes ride on to the main tube that plugs into the hitch (the clamps are not stiff enough). I am running the expedition one tire carrier with 37" Falken Wildpeak A/Ts on ATX slabs (with 3.5" backspacing). With this combination, the rack fits fine without an extension. I cannot fold the rack up for stowage; however, after removing the bikes, I can still open the tailgate if I place the rack in the down position.
The initial rack that I wanted to purchase is the Kuat NV2. I liked the idea of having a bike maintenance stand built into the rack in addition to the feature they use for eliminating the rattle. I haven't observed a similar anti-rattle feature in any of the other bike racks of this style. The unfortunate issue is this rack would not fit on my setup without a hitch extension, which I was trying to avoid since I wanted the bikes as close to the back of the jeep as possible.
The Thule rack is easy to install and remove with one person (I do not have the extension to allow mounting 4 bikes so I can only speak to the main unit that accommodates 2 bikes). One just needs to insert the rack into the hitch, install and tighten the bolt and place the lock on the other end. Putting the bikes on the rack as well as removing them is very easy, the only thing that I have to watch our for is the pedal location since the forward bike mount is so close to the spare. Though it does come with a lock, it isn't much of a deterrent (yes I speak from experience). I also check the bolts on the clamps periodically to make sure the tubing the bikes are mounted to doesn't slip while I am driving.