I like my truck camper because it can easily go wherever my car (small Subaru)can go. Of course it takes more space than a Smart Car :) I drove cross-country during a month's vacation. I was able to park at all the fast food restaurants and tourist attractions. When severe weather warnings arose, I stopped at a motel (needed only one regular parking space). When the wind was howling and the rain pouring down, we appreciated a hot bath, movie channels, and a ready breakfast. When the weather was clear, we appreciated seeing all the stars during our middle of the night strolls to the loo. Out of 30 days, we had to cancel 4 nights of camping due to weather. Once, I was too tired to keep driving and we stopped at a motel. I averaged between 13 and 15 mpg.
I think my truck camper gives me the best of three alternatives. Since it is a pop-up, I have some of the feel of a tent, without having to spend time cleaning and stuffing the tent. As in a motorhome, I have conveniences such as power and my own furnishings. If I choose, I can eat at a restaurant or sleep in a building.