I have found a rotary cutter that I really like and wanted to share the find with all of you. Being left handed means that I have always had to swap the blade side on my Olfa cutters (which I will definitely continue to use), but Martelli has a left hand model. So, as my own birthday present to myself I decided to treat myself to a 45mm version. http://www.martellinotions.com/ I did about 5 hours of cutting with it over the last 24 hours and I have to say that there is no sign of discomfort in my wrist. The design is supposed to be great for hands that have arthritis, carpel tunnel syndrome, tendonitis, or hand fatigue. I am still in my early testing, but I think this is a true thought. It is not exactly like using the straighter handled cutters, so there is a small learning curve. I also think that I would avoid using this cutter if I was tired, but not because I think it is any more or less dangerous than others. The thing is that I found that when I was distracted I cut a few more "curved" edges. The reason for this is that the whole cutter has a unique shape and if my hand was not positioned correctly the weight seemed to move the blade away from the ruler. A little practice did improve this issue. What I liked best are that I really was able to cut through 12+ layers of fabric without any drag and the cutting is finished in record time for me. It will be very useful for cutting strips and large quantities of blocks.
Back to my thoughts on the Olfa cutters. I do believe that it has one feature that I real like, especially if anyone else is cutting with me. When I release the handle after cutting the blade automatically goes into a safety status. The other one is supposed to have an automatic release guard, but it did not seem too automatic to me. My Olfa cutter is also going to remain my cutter choice for workshops because the straighter, flatter handle makes it easier for transport.