I guess covering is really a personal preference. If you do cover, I suggest you DO NOT use tarps. Tarps don't really breathe like RV covers do, so really the RV covers are best. I prefer the kind that have tarp material on the top, front, and rear, but have a breatheable material on the sides. I do prefer to cover, but again, that's just personal preference. Really though, indoor storage is the ultimate best.
2007 T-286SR Cherry/Granola, #6236, original owner, current mileage: 9467.8 (as of 5/26/19)
1997 T-2653 Blue Denim, #5471
1979 12 1/2' MC, Beige & Avocado, #4639
Past Sunlines: '97 T-2653 #5089, '94 T-2251, '86 T-1550, '94 T-2363, '98 T-270SR