I just used it for the first time on applique (as mentioned in the other thread, butterflywing) after watching Sharon's applique and binding videos. The line of glue is very, very tiny using the metal tips I got at Joann's. It came with 4 different sized tips and two plastic bottles and it was in the fabric paint and pens aisle.
I heat set it and then did the blanket stitch. If I didn't know there was glue there would be no indication when sewing that there was. No problem with the needle, no gumming or flaking. I could see that maybe someone would have a problem trying to sew through not-quite-dry glue but the bead is so small and dried that I don't see it causing any issues.
I may try it on seam matching when it's VERY important that they be exact and not move when sewing.
In her video she shows a quilt that the applique was done with glue then stitched and has been used and washed and it's just as secure but the applique is loose in the middle like hand applique and gives it that soft look. She also has a video of doing applique on a long arm using the glue.