I had a similar question when trying to decide.
We are hikers and travelers so we don't live in RV parks or in the unit if we can be outside. We try to stay in the national parks or state parks if possible. Usually there is a shuttle to get us to our jumping off point so we don't tow anything. We wanted a comfortable place to sleep and a easy unit to driver with good mileage, (price of Desiel is to high everywhere).
Advantage B+ a bit more space inside, separate shower, a little more storage.
If I were choosing a B+ it would be LT Unity Twin bed, I like the separate beds with the ability to make King size. I like bath on one side toilet on the other side. I like the two separate living spaces and ability to have a third bed. Good storage. Bad; not as many windows as a B. seating for two; if you have guest they really can't see out while traveling. Not to big but still things are sticking out so you have to be careful not to cut corners.
Advantage B better fuel mileage, more windows so brighter, easier to drive, under 24' feet so nearly always accepted in national parks, tunnel Zion restricted height and width restrictions, parking in town nearly always legal (I didn't know there was a size restriction)
B; I own a Pleasure Way Plateau TS, great for two people, galley on passenger side better layout for when you are parked (visit with fellow travelers). We use the back sofa as a queen size bed. The back sofa is great to have the grand kids with us, easy to look out all the windows so they never miss the action. If you are organized storage is not a problem, I would like to get the tire out in a continental kit to free up more space but that adds length which may be a problem in some of the Natioal parks, they prefer 24 feet or less. If you decide on either a B or B+ get the factoy installed Solar saves a lot of trouble. I would opt for the on demand water heater. If you have lots of money deisel heat, water heater and generator.
Liesure T., Pleasure Way, galley on passenger side. Road Trek, Airstream Galley is on the drivers side. Build quality on all these units appears to be about the same.
Wini had some problem a few years ago but seems to be back on track.
If you look hard enough you will find + and - for each it is up to you.