I think I have tried most the of circle cutters on the market. This is simply the best circle cutter there is. I don't have the 13"x13" glass mat. I have a smaller one, but this works great. HINT: If you have a problem with your paper slipping on the glass mat, keep a roll of blue painters tape handy and tape your paper down. Voila, no slipping and beautiful circles. I needed a huge circle once and ended up drawing around the outside edge of the template and cutting that out. I can't wait to get the oval and the rectangle templates that go with this cutter! The blades last quite awhile, but keep a supply on hand, there's nothing like a fresh, sharp blade!
I bought the oval template and didn't realize that I needed this lil bugger. Great investment though. The swivel handle makes it easy for you to keep your hand on the cutter and never have to reposition your hand. Only suggestions I have are (1) buy a glass mat as other mats will make cutting much more difficult. (2) keep the plastic protective blade cover so you can replace it when you are not using your cutter. The handle opens for storage so there's no excuses that you lost it!
I have played with this on thick cardstock to thinner patterned paper, and I absolutely LOVE IT! The blade is very sharp to handle any kind of paper. The track is also an essential part. It is very smooth and allows the blade to do its job. I also cut on the glass mat, which allows the blade to glide through the paper as well. Ek Success has made an awesome product once again!