I'm on my second one (had one on the first trailer and liked it so much I got one for the current one). I think it is worth the money - nothing like washing the RV, putting it away, then coming back and taking the cover off a month (sometimes longer) and it looking just like when you parked it. It also does help to keep the heat down inside.
I haven't had issues with the rubbing or the cover coming off, so can't comment on that.
2013 Georgetown 351
Much more significant other....
2 Kids and a dog that rules!