I know this topic has been covered many times. I purchased a 2016 Fleetwood bounder 35K this year with a 22,000lbs F53 suspension. These are very tall rigs and very top heavy. I performed the cheap...
I had porpoising and roll in my 26,000 lb Bounder and installed Bilsteins with the lifetime warranty. Immediate improvement. The shocks I took out were in pretty bad shape, leaks, total failures. That was 11 years ago and when I sold the Bounder early this year, the Bilsteins were still working well.
Bilsteins that came with many RVs as they left the OEM's factory over the years are not quite as good as their aftermarket product so you may hear some dissing them.