Me and my girls were talking about this last week on our camping trip. We have a folding caravan which I think is the best of both worlds. All the comfort of the caravan but with a canvas lid which makes it still feel like camping, with the sound of the elements outside.
I did gaze in wonder at the caravans, but I wouldn't want to tow something that big, and I'm not sure I'd ever want to sleep on the floor of a tent again.
I love my trailer....