Here's my 80 with a Camping Labs medium RTT and changing room.
Plusses: Its affordable. It is fairly weather proof, I have been in snow storms, dust storms, thunderstorms, hot weather, single digit weather, and just about everything in between. Storm force winds and rain cause a bit of seepage in some of the seals but that was about it. The changing room sets up rather quickly and provides a good place to cook or hang out of the weather or sun and since it is basically three sided, you can open the rear hatch or tailgate and have use of the back of the truck from inside.
Minusses: The spring steel awning arms aren't all that springy, and get bent pretty good in heavy winds with the awnings up. The changing room has no floor or 4th wall like previously mentioned so it isn't bug proof and hard to heat in cold, cold weather. The quality of the zipper on the cover is marginal, I had mine catostrophically fail this summer from dust leaving me in the midst of a two month trip with a flapping cover. Mine has developed a saggy floor on the overhang side, basically drooping in the middle. It is rather tall and blocky when folded so it creates a decent amount of drag, not an issue really if you mount it above the bed railson a pickup but noticeable on the roof. And similar to most any RTT, it is loud in high winds. Also the lack of enclosed entry to the tent makes getting in or out in heavy downpours challenging and usually allows moisture into the tent onto the mattress during the effort.
