Hi Chris,
I've used a double needle for t-shirts and it's not very hard, although you may have to play with your tension, it works great for knits.
However, I haven't used it in a quilt. The thing is, the underside of the stitching looks like a zigzag stitch and isn't very pretty (at least mine haven't been) Also, because there's just one bobbin thread if it gets snagged or clipped, most of the stitching can come right out. Ask how I know that!