I've owned 3 fifth wheels and only this last one was bought new. Three years ago we bought a Grand Design Reflection 27RL new from a reputable dealer. We were in a hurry to take delivery and leave town on our first trip. The salesman told us to get out and enjoy the trip, shake it down and let them know of any problems.
We had several issues but I believe some of that was just my fault for not checking things out good before we left. Some of the issues I corrected myself and about three others required trips back to the dealership. The most critical was the fresh water holding tank would not hold one gallon of water. The tank had to be replaced. The other critical issue was the brakes had massive amount of thin runny grease leaking out of the seals and all four brake clusters had to be replaced. You cannot remove grease from a brake shoe. Grand Design was very easy to deal with and addressed all of our issues quickly. The dealer was also very good. All RV's are manufactured very rapidly and there are no quality control processes before it leaves the factory. This is dealer responsibility and I did not allow the dealer much time. I highly urge you to be sure the tanks are filled, all plumbing checked out and all valves are working. Be sure all systems function properly!! There will be issues both large and small. Grand Design builds a good trailer and back their product !! Just check everything out real good before you pull it off the dealers lot. Right then is the best time to address issues.