I have a 1/2 in. one -- didn't much care for it because it kept slipping. Am going to try those little stick on things that keep your rulers from slipping.
Someone mentioned having trouble keeping track of where they are supposed to cut. Have you tried the wonderful blue painters tape for a quick and removable marker? I use that on all my rulers. It zips right off after the project is done. I also use it for marking straight lines when I'm quilting, goes on fast and comes off just as fast. Also can be moved/reused on fabric.