The good thing about rotary cutters is that you can cut fast, but you can also make mistakes fast. So until you master the art of using a rotary cutter and a ruler, take it slow.
- safety lock
- easy nut to replace blade
- Ergonomic handle
- a light?
Firstly, buy what you can afford. I started off with a small A3 cutting mat. It has been a faithful companion, and it is only now after quilting for a year that I have invested in an A1. Make sure you get a self healing mat and not one of those mats from the chinese shops.
I like the tandem idea of two rulers. One for cutting and one for measuring. I use a ruler with my left hand (small 5 1/2 inch square) to measure then secure the left hand one (4 inches by 14 inches) to cut the sash or strip.
What equipment do you find "essential" for machine quilting?