I have the large Olfa and love it. I have it sitting on the top of a small table right by my sewing machine. When I am cutting the pieces for a project it is perfect to have it right next to me. Now if I could figure out how to press my seams without getting up to go to the ironing board... Egads am I lazy or what? No, really it is a great situation for preparing the many pieces for a project and know that my cuts are precise. Haven't seen the Martelli, but will now take a look. Speaking of Martelli, I bought one of the 45 mm rotary cutters at a quilt show 3 years ago and decided I didn't like it. So with my present project I decided to give it another try and I love it! Has anyone else used their rotary cutters? I'd be interested in knowing if the ergonomic feature helps when cutting many pieces. So far I am still getting used to the shape.