In my opinion, you will find you get tons of people that are for covers and tons against it. I haven't nearly been RVing as long as alot of folks on here but, growing up, my parents and grandparents never covered their RV's. My neighbor, his parents, and his inlaws all cover their RV's and have forever. I got a great deal on a cover so I thought I'd try it out. It's a CAMCO cover for my 36' Keystone Sprinter but, it works great. We have terrible winds here in the winter but, there are straps that go under the camper to the other side and hold it down tight. There are also buckling straps on the rear and front of the cover to hold them tight and there are breathable areas within the cover that keeps the air flow moving and the cover never flaps around. We have had no issues.
Personally, the only benefit I saw was that it kept it clean over the winter and I saw no damage from the cover.
Good luck sorting through all the opinions!
2012 Keystone Sprinter
Still sticking around for the good people and advice.