It's not just about where "you can take it" but how you will get it there. One suggestion would be to camp out at a local campground and walk around and talk to different campers. Also, watch as new rigs pull in and set up camp. Very instructive! We're middle of the road with a 27' Class C. We're still trying to figure out what people do with all that extra storage in their "basements". :)
We like all types of campgrounds and our moderately sized rig allows to get just about anywhere. (There are definitely places we would have had to steer clear of if we had a bus).
Todd