The Rvision we had, (2004 Bantam 19) had floors that I would characterize as softer than normal, but were structurally fine. They state in the Rvision manuals that these trailers are not intended for full-time use, and one of the reasons is the softer floors.
I've read others complain that after years of use the main walkways get compressed and you can see the difference between high traffic and lesser used areas.
Walk around on your tippy toes in athletic shoes and see if the softness is consistent throughout, or if you have actual soft spots from water damage/moisture.
2015 Coachmen Freedom Express 292BHDS Blue Ox WDH
2015 RAM 1500 4X2 CrewCab, 5'7'' bed, 3.93 gears, 5.7L 8-speed VVT, Payload 1608, Max tow 10,400