I don't use mine often, but it comes in really handy when you need to square up lot of blocks. I recently finished an Anita's Arrowhead quilt top. Each block needed trimmed down just right. I could cut all 4 sides without having to move it by using my rotating mat, so yes, it's worth the cost even though I don't use it often. I have the green one with the little black circle thing on the bottom and it works well for me.