I have tried several...the circle scissor, the fiskars shape cutter, and several others. The only tool I've found that's easier to use than this one is the CM circle tool. However, for the price difference between the two, this is the best choice between the two. There is a slight difference in how easy it is to use, but a huge difference in price.
-On a glass cutting mat, this cuts beautifully.
-Circles are smooth on the edges, not slightly town, or imperfect as I found happened with some other circle cutters.
-Matting is easy to cut, and it's easy to keep track of what size you're cutting (unlike the coluzzle).
-Does NOT work on a self healing mat. MUST be used on a glass cutting board! The packaging did not state this (at least when I purchased mine) but the instructions do.
-On mine at least, the 'maps' in the center do not line up properly. Until I figured this out, I ruined a couple of photos.
Thanks to Flamingo for helping me figure out the sizing issue...I really appreciate it.
I have had some issues with my blade carriage...I am currently contacting EK Success about this...I have heard their customer service is second to none, however!
Hope this helps!