If you insist on covering the unit, please be sure to check it once in a while for wear, from rubbing. You can do a lot of damage that way. And condensation has been reported as a problem, so if you have to cover, might look into some of that dry stuff (someone help me out here, you buy it at Walley world) and it sucks the moisture into a bag or something! You can tell I have not purchased any yet!
No covering going on here, did it one time many many moons ago on a prior TT, it blew off the first good storm with very strong winds, was flappin all over, took it off and never looked back.
Hear the custom covers are very heavy, actually saw one on a unit the other day, looked like it fit very nicely, and tucked way under the unit, maybe the wind will not catch it.
Rather have the unit accessible, it is, our spare room, when company comes. They can use it, or if they hesitate, Al and I have NO problem giving up the bedrooms in the house for our guests and punishing ourselves by sleeping out there ourselves!
Good luck in your decision.
AND WELCOME TO THE MOC!!!