Dual pane windows are worth every dime to me, but all dual pane windows will develop leaks between the panes eventually. While they can be repaired by several companies, the charge to repair frameless windows is a lot most costly per window that non-frameless.
I had all of my windows removed/resealed in Hudson, FL a few years back after several had fog between the panes. I was sure glad I didn't have dual pane frameless windows.
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-PT50X, TST Systems 507 TPMS, RV Flex Armor Roof