Their covers can warp and bubble. If you read the fine print of their warranty, it specifically says that cover warping is only covered at the time of delivery. They added those big clamps to try to prevent the warping. Also, the plastic cover arms are weak and break a lot. Those are not covered beyond 90 days. You can't even find a copy of their warranty online anywhere. They used to have it up and we would point people to read it when they were looking at those. Now you can't find it anywhere.
Bottom line, they are a shady company that does not warranty their covers that warp. They are waaay overpriced for what they are. They use dishonest sales tactics. They usually don't have good support after the sale. I recommend making them show you a copy of the warranty and post it here for everyone to see.
If you want that kind of hot tub and cover maybe check out Tuff Spas. Have heard good things about them.