There was a discussion of this about a month ago. I've used it, I thought it was great. Especially useful for thicker batts that don't lend themselves to zig zagging. However, a great tip. Several quilters suggested just buying one sided fusible in yardage and cut that into long strips and use that instead. Certainly cheaper.
BTW, the only poly I've tried this on is Quilter's Dream. I hesitate trying it with an all poly batting because it might melt.