Yes, I just finished McTavishing a bed-sized quilt in the open area around applique for a client. It's thread, time, and labor intensive, but so worth it when you apply it in the right areas of a quilt. I agree that it shouldn't be done right next to feathers, but there are so many ways to use this technique! Actually, I agree with everything Carla P just said! :D But wanted to add my own enthusiasm as well.
BTW~my client received a blue ribbon on the quilt that I did the McTavishing on. I've heard that judges are looking for something new, and a little different from the other, more common forms of all-over background designs such as meandering. I'm happy for her that it worked to her advantage. :)