I have an Olfa 45mm and Fiskars 45mm - but my favorite is my Kaicut 45mm rotary. :)

For use on their rulers, which I love, is the True Cut ergonomic rotary cutter. I use the 45 mm Olfa the most but also use the 60 mm fairly frequently. If I didn't already have them I would switch to the ergonomic style. I did learn on one of The Quilt Shop videos you should cut with you pointy finger on top of the cutter pointed toward the blade. I will try that next time I need to do some cutting.

I like the Olfa 60mm

45 mm Olfa I have an old 65mm one (think it's fiskars) but I can no longer find blades so I use it to cut stabilizer or other non fabric items that I need

45mm Martelli cutter. I can cut all day without discomfort in my hand or wrist.

I own 3 different Olfa cutters, but bought a Martelli in April and have not used anything else since! It is amazing!

Recently I purchased the Martelli 45mm bent handle and love it! Hope they come out with a 60mm soon. When Martelli had a 1/2 price sale, a couple of neighbors and I purchased the 50-pack of blades and split the pack.

I only have the Olga 60mm and my daughter has the 45mm. So, we're covered no matter which size we need.

I use the 45 and I get a lot of use with the 60 . I use the 60 mostly for squaring of my quilts.

45mm Fiskars