Martelli is an Ergonomic cutter and it is supposed to be easier for Arthritics. I have a niece with MS who really loves it .. makes it much easier for her to cut.
Just be sure that your replacement blades are NOT the ones with the notches - I forget which one has the 3 notches cut out so it fits the rotary cutter). They (Martellis) recommended that I not use them in any of the rotary cutters that don't need it because the blade will dull quicker in 3 spots.