Well, I know the center bath is a good solution for us. That set up keeps the tanks and a lot of other potentially heavy things close to the axles--always a good thing. It also allows people to access the bath from the front sleeping area or the rear bedroom without intruding upon other's sleeping quarters.
There are two set ups for a center bath from that era, the walk through and the side bath. Our 1988 34' has a walk through bath. My dad's 1989 34' Excella has a side bath.
The walk through obviously gives you a larger bath--ours is basically the size of the rear bedroom. Full size tub/shower/washing machine closet on one side and sink/toilet/full size linen closet on other. In (personally unproven) theory, you could have one person using the sink, one using the toilet, and one in the shower--a lot of space in this trailer is dedicated to the bath. Doors are on both entry points to the bath from the rear bedroom and from the kitchen.
Side bath equals much tighter quarters in the bath. It gives a much smaller shower and the toilet and sink are much cozier. It works, and for the time you spend in the bathroom (small amount, relatively speaking) it makes more sense. In the case of my father's trailer, he has a 3 door wardrobe opposite the bath--a good deal of storage.
If I had a choice between a center walk through bath and a center side bath, I would pick the side bath simply because space is always at such a premium and this setup seems such a better use of space.
Hope this is somehow helpful to you in your search.
Easily distracted by shiny objects.