I have a 2003 Starcraft 21RB which I bought used. I love the floorplan....mine has the bunk over the wardrobe rear side across from the bathroom. I use this bed area mostly to store my suitcases, shopping bags, etc. The rear and front beds are both queen size.
IF I changed, it would be mainly to have a slide-out model for more space inside.
Otherwise, it's fine. Especially going from a Class C with slide-out.