Plywood is not higher quality compared to the proper OSB, I would take a outside rated OSB over plywood any day, its stronger (for the same thickness) way way more resistand to delamanation due to moisture, water proof resin/glues to make it, more dimentionaly stable than plywood, its cheeper, and more enviormentaly friendly. there is a reason OSB has been replaced plywood, in every part of building construction.
for me it is about finding the floor plan you can use for a long time. most of the reasons people buy new rv's is because the floor plan no longer works, weather it is because they have kids, get rid of kids or it just doesnt work like they thought it would.. take your time to figure out what you need for your situation, then look at anything besides jayco 😁 seriously though, look at the quality of the interior stuff, like the kitchan drawer construction, the trip work and cabnets..