I had an original Olfa 25 years ago and cut myself, therefore I learned to be more careful. However, when the Olfa Ergonomic cutters came out - I bought the 45 and 60 sizes and love both.
For some reason, I have a problem with the Martellis, but have heard others that love them.
I think you need to try them at a show or at a LQS, if possible, to see which one you prefer.