Most folks buying a new unit will indeed have to work out the kinks, so to speak. The trick is to get to them before long-term damage is done.
I, for one, bought new - Rockwood 8280WS (ultralight fifth wheel.) Love the unit. Been full-timing in it since picking it up new two years ago. Warranty issues/repairs? I put an adhesive strip across the joint of the roof and the end cap, as the caulking had shrunk and was gonna leak. Total cost: $50. And I still have 40+ feet for anything else similar that might occur. Oh, did the same "repair" to the caulking around a vent. Just the nature of the materials used on RVs for sealing.
Two items replaced by the good warranty folks at Rockwood. One, the side window on our living room slide out broke into a million pieces one afternoon when closing up for the night. We didn't slam it, it just hit the bottom and kablooey! Rockwood FedExed me a new window to a dealer 90 minutes away that we were going to pass by on our way north. I booked the appointment, arrived 15 minutes early, and in 90 minutes we were back on the road with a new window.
Fix #2 is a pet peeve. We have day/night shades. You slide them up and down every day, on STRING. They are guaranteed to wear out and those strings give out. Then you can buy a repair kit and try to fix them yourselves (we couldn't as the end caps had been glued on!) or you can replace them. I called Rockwood and they told me those shades were still under warranty. So, I sent them photos of the failed strings and the damaged shades, and they shipped me three new replacements. Oh, I originally called the shade manufacturer who said if I sent them a shade and they could not fix it for me, they would send me a new one at no charge. And they did - I got a new one ten days later.
And that's it. Two years, over 10 miles on the fiver, and we live in it 24-7. In my book, you can't beat that with an ugly stick. I bought from a good dealer who prepped it well. Took it for a three day trial run, and told the dealer I would bring it back for repairs. They said fine.
I called them after the three days and reported "no problems, no repairs needed." They were not surprised in the least.