We've had a park model (33 x 12) for about 20 years on a lot we own at a campground, and that's been more than big enough. On the other hand, most of my longer distance camping has been from the back of a motorcycle. You learn pretty fast to cut weight and volume when camping that way!
I'm new at this, but I think the change from voluntary CCC reporting via the RVIA to regulated OCCC reporting means the numbers should be reasonably accurate. The regulations even require a dealer to add a special sticker if more than 100 pounds of aftermarket stuff is installed. If so, I suspect I don't need to weigh a unit myself. I realize I still should weigh each axle and wheel after loading up.
All of the units I've looked at have at least one full width compartment, and one has at least two. I'll have to pay more attention to this, though.
Thanks for the replies!