As Tartan stated, the flange binding allows you to hide your stitching in the ditch of the flange so it will look much nicer. I and my friends have found the McCall's direction to work well. Video is included in the directions.
http://www.mccallsquilting.com/blogs...ng-by-machine/
When sewing thru all that bulk. I believe it is impossible to get the stitching to be perfectly straight.