What you are referring to is typically referred to as an egg or shell camper.
We looked hard at these but no slide and too small for two adults and a 70 lb. Dog.
Generally lighter in weight with fewer seams they get good reviews from their owners. But they were too small and tight for us.
We own an old school stick and tin (aluminum) 2010 model with over 40,000 miles on it.
Basically you buy the floor plan you want. It is your biggest concern.
Good luck