Before I got this 5er, I used the Adco covers and my experience(s) showed me that tightness is the one thing you have to maintain in order to get them to hold up well. Any movement of the cover will ruin it in short order and sharp corners will make keeping them tight enough a difficult proposition. Even with them very snug and protected from sharp corners, about 3 or 4 years is the best I've ever gotten out of them.
My 2 cents, your mileage may vary...
2 Cats; J-Lo and Ragamuffin :R
2014 Thor Tuscany 40RX DP
2011 Ram 2500 Longhorn CTD HO
2011 Keystone Cougar 318SAB (now gone)
2008 FunFinder X 210WBS (Sadly gone)