we have the ADDCO cover for our TH. this one is going on 4th season.(we do have a walk on roof with a ladder built on that make it easy to cover)
the sun in north west co here is brutal,then the sun reflecting of the snow on top of that,.
the sun is as bad as vegas where we keep a boat.
my son has a T H very similar to ours. sam size and brand. ours is aluminum and his is fiber glass. his (no cover) is starting fade in spit of waxing each spring.
we cover our at thanksgiving and don't uncover till around memorial day.
i am happy with the cover and defiantly helps and protects the trailer from elements. we use it as a storage cover. i don't think any cover would be practical to use in camping season. we use our T H for a week or so each month. this is would where the car port style shine.
any type of cover has to help. i think most over look the heating cooling cycle that goes on each day. this is natural. not much you can do, but shading when in direct sun has to help as surface dos't get as hot and must minimize the the expansion-contraction some, and shade from harmful U V rays