Rotary Cutter are not all equal. I've looked at quite a few brands and listened to a number of quilters. Ergonomics and blade saftey are my primary concerns. The KAI Rotary Cutter came out on top due to the automatic blade shield that covers blade when not in use. When you do purchase a rotary cutter, buy the manufacturer's replacement blades not generic ones. Pay the extra money and you will find that they are sharper and last a lot longer. Make sure that you use a quality cutting mat.
Michael