Well I can tell you first hand that doing the Mor/ryde IS upgrade will kill the Lippert frame warranty, but it sounds like they've already backed out, so sounds like nothing to lose. Because of the options we put on our RW and that we live in it 9 to 10 months at a time we travel heavy, like 500 Lbs plus over the 16.5K Gross. So we've upgraded to the 17.5 wheels with "H" rated tires and the Mor/ryde IS 8K system and couldn't be happier. If we had to do it all over again, I'd go with the cheap Marabombs, them before leaving the Dealer install the 17.5s then go directly to Mor/ryde for the IS install.