With the quilt I'm working on now, Bonnie from the www.quiltville.com
site recommends the EZ angle ruler. I wondered to myself if I REALLY needed another ruler/gadget? I did the math. With piecing by cutting squares, drawing a diagonal line down the middle, sewing 1/4" on each side of the line and then cutting apart I'd be cutting my squares at 2 3/8" for the size units I'm making. If I cut squares then cut them on the diagonal like it is traditionally done..again I cut at 2 3/8". With this ruler I cut the strips at 2". I'm using 80 strips. 80 x .37(3/8")= 29.6 With this ruler I'm saving 29.6" of fabric!
That adds up! I spent $5.99 for this at Joann's..(didn't have a coupon and wanted to get started). I'd say that's a pretty good investment! I had to keep the instructions setting out until I cut a few strips and got used to knowing how to position it. It has good instructions too.