I have not used the walking foot yet. I have been trying to research it with little luck so far. what does it do?

It feeds both the top and bottom fabrics through the presser foot area evenly.
This really helps when you are quilting your quilt.
You will find no puckers if you baste your quilt well. :D:D:D

Your walking foot moves the bottom layer of your quilt along with the top of your quilt so the stitching is even. No walking foot makes the back of your quilt nastyyyyyy !!

My machine has a built in "walking foot" and I use it for everything. It is great for piecing, sewing specialty fabrics, anything that has any kind of possible slippage or stretch. I think it is a must have like the differential feed on my serger.

I will put it another way, I would not quilt in the ditch, do straight line quilting or sew a binding on without a walking foot. Its that simple.

The walking foot feeds the top layer of fabric and at the same time your feed dogs feed the bottom layer. That way you don't get puckers. It's a wonderful help when you're piecing. Have you noticed that sometimes the top fabric ends up longer than the bottom fabric if you don't pin well? Also great for stitching in the ditch and attaching binding !

ok sounds like it is worth changing the foot when sewing the batting...another question. Can you I sew pieces together with the foot so that I do not have to keep changing the foot?

Yes

well yes you can sew pieces together but i love to use my 1/4 inch foot for that. i use my walking/quilting foot for adding binding too but it's difficult to get it 1/4 inch with that.

mine says to sew slower with the walking foot on-so I change it out and do not use for piecing-pedal to the metal time,lol.it really takes about 30-45 seconds to change out