GD has had a pretty good reputation, I know a few members have had some issues but over all very positive. Jayco has a good reputation too, but with a bit more baggage because they are an older company. They, within the last year, sold out to Thor, prior to that they were the largest family owned RV manufacturer.
As with any RV there are lemons and the Friday Gilligan Specials out there, you need to do a detailed PDI before you sign any purchase paperwork - after you do that you are the mercy of the warranty gods.
Two Wire Fox Terriers; Sarge & Sully
2007 Winnebago Sightseer 35J
2020 Jeep Gladiator Rubicon