The site iRV2.com has an owner's forum for many manufacturers. You might want to read through them to see what the problems are with RVs.
Go to the dealers in your area or to RV shows and look at some of the construction, particularly how the drawers are made and how the trim lines up. What are the cabinets made of? Many mfg. use a lot of staples to hold things together. If a mfg. takes pride in what they build it will be obvious by just looking at the obvious things. Then pick up brochures and study the comparisons of how the frame is, etc. You'll soon get the idea. Good luck! :)