When I bought my 5.5 in 1995, I bought the exact same blue trailerable covers from Salty Dog. I have still have them, still use them in hot TX sun. I much prefer the UV damage to the covers & zippers than to my gelcoat, lines & tramp stitching. 2-3 times taken to sailmaker to repair zipper or whatever. Hulls still looks great. The material breathes, so no mildew, heat is not a problem.
, imho.