I have been FT in my new Designer since mid-August and no water leaks at all. We had 5 inches of rain in 12 hours a couple of weeks ago. I did have to hook up and move my Designer after the rain and level up my new gravel pad after the rain. It settled a bit on one side, but you sure can't blame that on the Jayco.
So far the only problems I have had:
vacuum system accessory broke
plastic clips holding the clear barrier on the storm door were cracked
one ceiling recessed light fixture lens fell out and broke
All covered under Jayco's warranty or in the case of the vacuum accessory, my dealer is working with the manufacturer to get me a new part.
Happy Camper here!
2006 GMC 2500HD CCSB 4x4 Duramax/Allison, Titan 52 gallon fuel tank, Prodigy Controller, B&W Companion Hitch
2010 Jayco Designer 35RLTS, Cummins/Onan RV QG 5500 EVAP, Progressive Industries EMS-PT50C, TST Systems 507 TPMS, RV Flex Armor Roof