I think the blades are like everything else. Everyone has their preference. I have never tried the Martelli blades so I can't comment on them. I prefer Olfa blades myself. My friend gets them for me at a good discount. I don't change my blades as often as I should because I just don't think to do it until they get pretty dull. A couple of members of my Quilt Guild own a shop that sell supplies for Home Ec classes etc. They have some sewing supplies. They brought a couple of blade sharpeners to retreat for us to try. The one we preferred was long and thin and you ran the blade down the groove to sharpen it. I don't know what brand it was. While it worked ok, none of us was impressed with it.
I guess for now I will have to continue to just keep replacing my blades.