I have arthritis and use the ergonomic Olfa cutters. I like the lock to keep the blade hidden until you need it. You need to replace your blades more often. As soon as they start skipping etc, it's time for a new blade. I have tried the sharpeners, waste of money as far as I'm concerned, because you just have to keep sharpening them more and more often. Most of us on here have discovered Harbor Freight and their carpet cutter blades. They work just as well as the expensive ones in the stores. I just got a 65mm Olfa at Joanns half price. Love it and should have gotten it sooner. You can cut so many layers at time and don't have the problem of getting hung up on the ruler.