Product review (3 stars): Initially enthused, but on second thought, I'm on the fence
These are a fabulous idea, and they do work well... and I like the company.  More than once they've included extra refills for me due to the size of my order.  I'm assuming that what you use them for is going to determine whether or not they are worth while.  I use them for contents of cat litter boxes.  After some experimenting, I found that I almost always need a foot to a foot and a half of the bag to make two decent knots and still be able to easily get the contents inside.  So that means I'm tearing it out, knotting it, filling it, etc.  So, I crunched some numbers.  I believe a refill has 32 feet of bag, which is going to give you a maximum of about 30 bags, probably a little less than that.  It's cheaper to buy doggy bag of the size I already know I need and don't have to guess at and in the long run is easier to work with.  So... good product, but I will likely go back to ready made doggy bags..