My wife and I backpacked in the mountains and tent camped for many years, finally moving to a pop-up when the 2 kids came along. After 3 years of enjoyment with that setup we absolutely can't wait to move up to a bunkhouse travel trailer. We're going long too, likely a 34 footer with outdoor kitchen summer of 2016 (gotta get the wife through nursing school first).
If it was just my wife and I, we'd probably end up with something like a 17 foot Casita. I love those molded fiberglass trailers for two people. But the reality is we have 4 and 5 year old boys and I want them to have their own space (for our sake more than anything else haha), as well as space to bring along friends and family. So we're going to rock the big trailer until they are out of high school. I want the ability to have 10 or 12 people up in there, a mobile gathering.
I guess we are lucky here in Tennessee, the state parks around here (and surrounding states that I've been too) are really nice, relatively updated and there are tons of sites for bigger rigs. That coupled with beach trips to SC and FL, we won't be missing out on much that we currently have access to with the pop-up. If we want primitive we'll go backpacking.
One thing, coming from a pop-up perspective, that surprises me in this thread is hearing people complain about the setup time on the travel trailers. What takes 30 or more minutes? It takes me 30 to 40 minutes to setup the pop-up and that includes hauling all of the******from the van into the camper and setting up decorative lights and flags. Seems to me a hard sided trailer could be ready to rock in 15 minutes tops but I've not owned one so I'm curious.