I reckon rotary cutters are heaps quicker than scisssors, but I find they do have limitations. Scissors I find are better for the fiddly stuff, like if you have to cut the fabric in a special shape, but I find a rotary cutter easier for just basic shapes or light curves, and definately quicker than scissors. I find it good that with a rotary cutter you can just lay down the fabric and you can see straight away that you have cut the line properly, but with scissors, its a bit harder to make sure its correct.