When I was still hand sewing on the back I use to round all my corners. I bought a rounding tool from Annie's Attic and used that. I found I had to pull WOF binding strips taunt around the corners when sewing onto the front of the quilt with machine. I was very happy with end result. I never tried to machine sew on the binding on then.
Now I make quilts for kids 45" x 60" and miter the corners and sew with machine.