My understanding is that the dual feed is for 2 layers of fabric and the walking foot is for "bulk" like quilt sandwiches. I use the dual feed for all my piecing but always switch to the walking foot when quilting. Looking at my little dual feed chugging along in action it really is there to help move the single top piece of fabric along but in my opinion it is far too "dainty" to be used instead of a walking foot. IMO the walking foot is well worth the cost and I figure these sorts of expenses need to be considered when you are deciding on which machine to purchase in the first place.