I have dual pane windows, not frameless, in my Designer and would not be without them. I full time and condensation has never ever been a problem. But,
At the 4 year mark I noticed a couple of them were fogging up between the panes. On closer inspection as the summer progressed I had 6-7. So what to do? I made an appointment in Hudson, FL the week ahead of my trip to Ft. Wilderness and had every window in the rig removed and reworked. It was a bit pricey but made more sense to me to do all of them when I was there. They are Kinro windows also. I don't consider them junk as a previous post said was mentioned by his dealer, but they could be sealed better. Other things on RV's are definitely junk, but I don't hear any mentions of dealers calling rubber roofs junk, but that is a topic for other threads some of which I have already written.
Would I rework all of my windows again - Definitely
Would I buy dual pane windows again - Definitely, but a part timer or weekend camper might not want to.
Would I buy a rubber roof again - Yes, only because it is all you can get, but would have it sprayed over by RV Flex Armor before I ever moved in. Just the cost of getting it right the first time.
Off of soapbox and ready for another cup!
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