a B is a world of compromises- the advantages are parking ( not only on the road but at home- we park in our driveway or sideyard), mpg, stealth and ease of driving.
there is a huge cost per cubic foot!
we have a PW Lexor TD on a Chev chassis- 10 years old ( 8 with previous owner), coming up on 100K.- it is 20' w/ spare... a chev van with a cap on the top (8'10")- std width. 6.0 vortec, 3 spd w/ OD. tow cap 5000#
It is awesome and we are very happy with our choice- the above aspects were prime for us- other considerations were size of bed ( 74" W x 75" long on driver side- 72 " on pass side) and make of chassis- we have other GM's so easy to fix and service- I already know the layout.
kick some tires- If you don't have alot of B's near you, the youtube dealer videos do a good jobs of showing the features- but watch how the sales guys jockey around the interior- gives a good idea of the space and how it is used
many PW's only have 2 seats ( swivel)- where as some Roadtreks have 3 or 4 seats- extra seats means the cabinetry may be floor to ceiling both sides
our tanks? 27 US Gal. fresh ( 225#) , 11 black and 27 grey...never too much or too little.
the build quality of the cabinetry and the layout of the plumbing, 12 VDC, 120 VAC and gas systems is top notch
We generally travel at 65 mph-ish on the interstate that gives good mpg ( 15 or 16) and handles fine.
We also drive mtns and coast roads- twisties and windies.
my wife has done solo trips from phx to California beaches- no problem..
some of the larger B+ or small C's seem to use space poorly with a galley in the rear and a bed/sofa in the middle of the RV- ours is in the rear and we leave the bed made up all the time
mike