First, we full-timed for 16 years in RVs with slides and didn't have one leak. It's not that common. Ones that experience leaks will comment on it but those that don't have leaks don't.
If you're looking at a toy hauler, travel trailer or 5th wheel, here's a good site to really get a feel for floorplans.
A friend had a toy hauler for his motorcycle. When he unloaded it they rolled out a carpet, put a drape on the rear ugly hauler door, spread out their recliners, bookcases, desk and had a very comfy den.
Good luck!
http://www.pplmotorhomes.com/5thwheel/toy-haulers.php