I just ordered one. I already have a slow feed bale net but figured I would try one of these. The one I have is a nylon one but doesn't fit as well as the Hay Chix seem too.
We've gone to all square bale nets and we love them! We aren't feeding anymore hay than we did when we flaked it out to them, but they are "grazing" on it.
I even ordered 2 for my FIL who was a huge skeptic when we started using them! Used a code, just don't remember where I got it :(