I've had Top Gun, Sunbrella, Surlast and vinyl.
Top Gun - Was a very well made cover and the material did a great job at keeping the rain out. My cover didn't have vents and I've been told that it should have or least that it's recommended as the material doesn't breath well.
Sunbrella - In my opinion the best all around material. I had a Sunbrella cover for 7 seasons and it still looked and worked great.
Surlast - This is the cover that came with my 07 X2. It left black marks on my seats, leaks like a sieve and I've had to have it sewn back up three times so far. I do like the way it fits on the boat but all the negatives convinced me to replace it this year for a Sunbrella cover from skiboatcovers.com.
Vinyl - Absolutely the worst material to use for a cover. PO had it made for the boat and it was scraped when I got it home.
When it comes to covers you get what you pay for. If you plan to keep the boat for a long time buy the best cover you can possibly afford. That way you'll only have to but one once.
Last edited by bturner2; 04-12-2011 at 10:21 PM.