3.5 stars I'd say. I got these on sale, price was ok but shipping was a bit much, each gets it's own shipping charge and comes in it's own box, unavoidable I guess. Anyway, they are not the same thickness or quality as the professional anti-fatigue mats we have at work, but again, that's fair enough at this price.
Ultimately I am happy with them, I put one in front of my lathe and one in front of my mill and I do feel that they offer a more pleasant standing experience.
One advantage is that they are not so thick as the professional ones, therfore less tall and less of a stumble-hazard. They are wider than the mats you can get at home stores that are aimed at putting in front of the kitchen sink.
Bottom line- if you are a professional business using these 24/7, get the real stuff and pay for it. If you are a light-duty user like me, only spending a few hours at most per week in front of your hobby machines, this is likely more than adequate.