I feel your pain. I'm in the same boat. Some brochures are helpful, some are not. Some dealers don't know their product either and give misinformation.
Initially, i was told the Jayco slx line uses identical construction to the regular Jayflight line, by the local dealer. Not true. Slx uses osb roof decking, jay flight uses plywood. I don't like osb for roof material, personally.
From what i have found forrest river xlite uses osb roof decking, and i know for sure they use osb for the dinette seats, bed and bunks. Not sure about the floor.
All have a crappy tpo or rubber roof with a 12yr warranty. Imo, another attempt to build a throwaway product. Can't get an aluminum roof, except airstream or kz sportsmen classic. I like aluminum roofs, again my preference. There are some good videos on you tube, but from what I've found so far, in my price range, the Jayco jay flight line seems to be the best built. Again, this is just what I've found so far and is only my opinion. Good luck.