I have a Q20 and only use the 96 foot on it. The 96 was designed for use on the Bernina longarms which have a hopping mechanism, so the foot moves up and down with each stitch. The 72 was designed for use on the Bernina domestic machines, so the foot glides across the fabric, so the adjustable presser foot height is helpful when moving the quilt underneath the foot. I do own the 72, but the only reason I bought it was to use on my 590 for a ruler foot class. Some quilters prefer the 72 on their Q20, so which foot to use is a matter of personal preference. If you plan to do ruler work quilting on another Bernina and only want one foot, the 72 might be a better choice.