Product review (5 stars): but I'm very happy with mine
I read a few complaints from people who said these are cheaply made or don't hold up to heat, when hot pans are set on top of them.  I don't know if that's the case or not, but I'm very happy with mine.  They fit my burners perfectly, they're very pretty and they keep dirt and dust out of the burner wells, which is what I was concerned with.  I will probably buying more to switch out, to match the changing seasons of the year.