It is rare that I sew something and don't use the #10 Edgestitch Foot. Sure you can use #5 Blind Hem for most edgestitching, but if you want to have the needle in the middle, you will need this foot. Not to mention, it moves around curves and lighter fabric better than #5 because the guide in the middle is not so long. Some folks like to do those things called crazy quilts with decorative stitches. Why not set the blade of this foot right in the seam and let the stitch line up perfectly on both sides? It is effortless, but you don't have to tell that to anyone. Don't forget to get the wider version of the foot, #10C, if you have a machine that sews 9mm stitches.
Bernina just added a special sole for the walking foot that has this same guide in the center. Can you say, stitch in the ditch? I can! Or have the best of both worlds with #10D, the dual feed option for 8 Series owners. I purchased the #10 Edgestitch Foot the day I got my Bernina with no regrets.