My experience is that I have used straight grain binding for over fifteen years and not had problems with fraying or excessive wear (and my quilts are mainly snuggle, lap quilts that get washed a bit). I have only used bias binding when I was binding a curved quilt and once when I had striped fabric that I wanted to "swirl" around the outside of the quilt and I achieved that through cutting it on the bias. But generally speaking, I personally don't bother to cut it on the bias otherwise. For me, it's simply not worth the extra time and effort. But as with all things quilty, do what works for YOU and makes you happy!!
