In WNY we get lots of snow and wind. I did buy a breathable cover. Not so much to keep rain/snow off but it does keep the tt cleaner and reduces the sun exposure. have not seen any places were the cover has worn the paint surface. As others have mentioned, it ties down underneath the tt. One place it really helps is the awning which traps water when retracted. This always causes mold to grow if not washed a few times a season. When i took cover off this spring, the was no mold because the cover kept it dry.
