HBP,
I have a friend who owns one. We've slept 4 guys in it comfortably and I actually think 5 would work just fine. The biggest problem I see is you need a place to dry the thing out if you are camping in rainy weather. As with any trailer setup you can only tow one thing behind your truck at a time so a boat and trailer wouldn't work.

We've done a winter camping trip the last several years and the little propane heater in that trailer cranks. Never been cold even at below freezing temps (of course the heater was running non-stop).

Oh ya, last thing. Nice to fall asleep in when its raining.

JMS