I find the neo-angle showers have limited elbow room; we had more elbow room when the shower was in the tub although we never used the tub to sit in. We also lost fresh water capacity when we got a trailer with a slide-out. Went from 50 gal to 32 gal. The slide is nice for interior space but there is a trade off. Be careful, some manufacturers include the 6 gal of water in the water heater in their total fresh water spec although you cannot easily use it if the tank is dry. The water in the water heater does add weight but isn't readily available unless you capture it when draining the WH tank.
That's my 2 cents worth. You'll have to decide which floor plans are best for you & yours.