I'm not sure whether I would machine tack a quilt. If you have your machine out, you could just do outline quilting or Stitch in the Ditch if you don't want to tackle FM quilting. I find that the machine quilted quilts that I have done handle repeated washings much better than the tied or tacked quilts I used to make. Tacking or tying allows the quilt to shift more during use or washing and eventually some of the ties or tacks start to pull out or tear the fabric. Some of my older quilts that were tied, I've had to machine quilt to stabalize them.