I had asked if anyone had ever used these and if they were good a couple of months ago. This is the first I've ever seen of anyone using them. Good to know.
If you want to save money on blades to to harborfrieght.com and order some carpet blades. They come 2 per pkg for $1.99 and they're the same thing as the 45mm blades that most of us use. I've been using one for quite some time now and they work fine. If you can't find them, purchase the yellow carpet cutter. It's $3.99 and comes with 3 blades---still cheaper than the LQS.