The walking foot #50, is imperative if you work with multiple layers, like quilts, or slippery materials, like satin. It is worth the investment, even though it is one of the more expensive feet.
The trouble with quilting on a home sewing machine is keeping the layers from bunching and maintaining an even stitch length. Well, that and just maneuvering the bulk of the quilt through your machine. The walking foot will help with both of these things. A walking foot is essentially feed dogs working on the top and bottom in conjunction with one another. As a result, there is a lot less puckering, bunching and shifting. Seems like a no brainer! Did I mention there are now three soles? One is like the standard foot and has a closed toe with an etched guide in the middle. The second is an open toe which allows you to see right up to the tip of the needle. The latest addition is a sole that has a guide, just like the #10 edgestitch foot. It is perfect for stitch in the ditch and edging!