I bought a 2005 keystone cougar 244 fifth wheel brand new, owned it 13 years without a single problem, so, followed the new owners of GD because of their success with keystone thinking I'd get the same results. Wrong. We purchased an Imagine 2600rb, and immediately had undercarriage problems, namely, collapsed springs and later, bent axles, which I had to pay for out of pocket, both because of under design issues, which, in 2020, GD corrected on this model. Since, I've had trim come off, both wall panels in the bedroom have come apart, plumbing issues sliding doors that beat themselves to death while travelling.
I have more, but they're minor, generally, count me as unimpressed.