Hi,
I had friends with several 'bad' designs, and they offered tips through the years on good VS painful RV designs.
Painful is having so little counter space that you have to use a 12" square fold up counter extension that is in front of the only walk in door, and have to remove that stuff and fold down the table extension every time someone enters to use the RR, or goes back out!
Not so helpful is that your stove and kitchen sink face the campground next door - or is mounted on the drivers side. Not a 'bad' plan when you camp in the desert, and never have neighbors to worry about!
So their next RV had a drivers side mid-bath that was not walk through, compact! IT had a rear couch facing the dinette, and kitchen was in front of the dinette. Back in 1987, they did not consider slide outs, so none of those.
My 1985 class C motorhome had a split bath, while the current 1997 that I bought new also has a split bath with doors. No slides in either. Slides where so new in 96 that I was worried about leaks, and torn up carpet (friend's 96 trailer had both). My split bath has two doors that are about 3' wide, one closes off the front, while the other closes off the bedroom - so the hallway is now in the middle of the bathroom. The shower is drivers side, the closet is passenger side, so is the sink. Toilet is next to the shower. It actually can be used with both doors closed to have about 2' square in front of the toilet, or open both doors and close off the hallway, and you have about 4' square area to get dressed in.
My friend's 96 trailer has a rear bath. It takes up the rearmost 3' on the passenger side and extends a little farther forward on the drivers side. There is a forward slide that starts about 7' from the front wall. The queen bed takes up the bedroom in the front 7' long section, for a private bedroom. I think it was a 31' long travel trailer.
My 1972 Coachman camper had the forward 3' dedicated to the wet bath! There was a orange plexiglass sliding divider between the bath and cabover section (it was the 70's) and the closet door was 2.5' wide and closed off the hallway toward the kitchen, leaving a large area to get dressed, along with the wet bath about 3' square, and sink on the passenger side with the shower hose attached to it, and the water heater beneath it. I sold that in 1995. Not to many current campers have such a large bathroom! I really liked that layout!
Have a great time looking for something, it is a lot of fun!
Fred.