quilterella

The 28mm is great for cutting circles or curved pieces. Although I have both the 45mm and the 60mm, I prefer the 60mm. It not only cuts through more fabric at a time, it is also easier to use for me, having problems with my hands makes using the smaller ones more difficult. With the larger grip area, it is easier to hold and not have to squeeze as tight.

Scissorman

I sell quite a few rotary cutters in my online scissor store. The most popular is the KAI 45mm Rotary cutter followed by the 60mm one which is great for heavy upholstery fabrics and Sunbrella Fabrics. I sell the 60mm to upholsterers, awning and marine canvas fabricators. The 45mm is much more versatile than the other two sizes for quilters. It is so popular that there are two accessory blades available for this rotary cutter . One is the 45mm Wave Blade, and the other is the inexpensive 45mm Pinking Blade which replaces the need for those finiky pinking shears. This Pinking Blade fits all the major manufacturers' rotary cutters.

Hope my comment was helpful,

The Scissorman