I have had the Martelli cutter for about 6 years now and I will never go back to fiskars or olfa. Love the cutter.
Blades seem to last longer, I can cut through more layers of fabric and there is less stress on my bad shoulders. I can even cut with it comfortably sitting down. I used Olfa blades in it for a while, but as sew connies says, it does not roll as smooth and is not good for the cutter. I bought a 25 pack of blades and shared the extras with all my friends that have the same cutter.