I've tried just about every solar cover known to humankind-except the liquid ones (Ugh!). What I've found is the warranties don't add up to anything--all they warranty are the seams, not the bubbles..and the bubbles are what fail. I've never been able to get more than 3 years from a cover, but always 3 years. IF you are religious about covering your cover EVERY time you roll it up, and wash it regularly, you MAY get a 4th year.
I've found the cheaper thinner ones work just as well as the expensive thicker ones and last just as long. I DO suggest you get a good roller, preferably an all-metal one. They last far better than the plastic ones.

You MUST store your cover in a heated space or it won't survive the winter.