Granted, I haven't owned a Jayco since 2004, but on our 2 Jayco Designer 5th wheels (a 1996 3030RKSS and a 2000 3610RLTS) we had very few warranty problems.
Jayco customer service at that time had a sterling reputation for dealing with any issues. One example is that, at the time, Jayco was using Todd Engineering power converters. Todd came out with a flawed new design that finally put the company out of business. When one of their converters would fail, I'd go to the dealer parts department, pick up another, sign a form and go install it. After the second failure of a Todd converter, I picked up a Progressive Dynamics PD9155 and told the parts manager that I was tired of changing out the Todds. He said "No problem", filled out the paperwork and that was the last of my converter problems.
Another example is that we had a Norcold refrigerator cooling unit fail on Memorial Day weekend, about 3 months after we purchased our 2000 Jayco. The dealer said that he couldn't work us in for 2 months. I called Jayco customer service and explained the situation, and the lady said "I'll call you back within a half hour." She did, and had worked us into a Norcold-approved independent repair facility that same day. 3 days later, we picked up the 5th wheel with a new cooling unit that had to be air-freighted in from Norcold.
Jayco always did right by me. Maybe that's changed - if it has, I'm saddened to hear it.
Rusty