Also, I think it's true that for applique on a piece that's going to be quilted, the stitches do need to be a little tighter, because quilting will draw up the background a little bit. Long ago when my mother taught me to applique on flat work, like dresser scarves, she always emphasized leaving my stitches loose. The first time I made an applique quilt and did that, the appliques kind of "floated" and the stitches showed.
Daffy