This!Twill is more of a woven fabric finish, diamond is a vinyl finish. The twill material is super nice and worth it imo. It also stays softer in the cold.
Really? Link?This!
Also, the twill has a lifetime warranty, while the diamond has a 5 year warranty.
Scroll down on this page and you will see what products have the lifetime warranty and 5-year warranty...Really? Link?