We've had zero problems with having enough interior storage.
For external storage (black hoses, fresh water hoses, sewer support, etc.) we use a hitch mounted cargo carrier and three totes. When we're staying longer than one night at a campground the totes go under the picnic table, the carrier gets folded up against the back of the B and doesn't interfere at all with finding parking spots if we go out sightseeing or to eat.
In our A we really carried a lot more stuff (and thus more weight) than we needed just because we had the space. It was all too easy to let stuff that really wasn't needed accumulate just because there was room.