15' and 5' RhinoFlex system here. I also use a 45 degree at the trailer connection so I can see what is going on.
I have been using this system full time for 3 1/2 years and the hose is holding up very well. No obvious problems.
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