I've used them for a few years now and only had one package of two that failed to perform and it was MY mistake. I put both blades in my cutter at the same time..once I realized my mistake I took one out and havent had any roblems with them...like anything else...use it correctly it will usually work and if you prefer to pay 10 times the price for something you can get thats equally as good or better...go right ahead. As for me, I'll use my savings for more fabric.