I have an older Go crank that I try new things to cut before I use my new Go. I have used other type of mats other then the Accuquilt mats. None have ruined the Go or the dies. The alternative mats may not last as long and some have cracked on first use. If I needed any mats I would try it out. I have a large stash of all size Accuquilt mats, all bought at low prices during the big sales this year at Accuquilt and Quilt in a Day. I rarely pay retail for mats. I stock up when I find a great sale price and free shipping. I got the 10 x 24 cutting mats a few months ago, two for $20 on a flash sale. Regularly $64.99 a set. I got five sets (ten mats), enough so I wouldn't have to look for sales again for a very long time.