I have always hated doing half square triangles. I would avoid them at all cost. Mine never turned out quite right. Then I saw a demo for this ruler. I didn't buy it then because I thought the price was just too much. I thought about this ruler for several weeks. I watched all the demos on line and really liked them. Jackpot---I finally found the ruler on line---the price was the same as the one I'd seen. I should have saved myself a lot of grief by getting the first one I saw. The good news is I LOVE IT. I found it very easy and accurate. Winner, winner chicken dinner. It certainly has my vote for "Worth it".