The Singer 15-91 is really nice for quilting. The bobbins are large so less bobbin reloading. The bobbin case is also in the vertical position, vs the 201 or 66 where the bobbin is in the horizontal drop-in position. The thread has one less 90° angle, which some quilters say effect their tension. I quilt on my 15-91 and love it, but my MIL quilting on her 201-2 and never has a problem. The 201 and 66 harp size is a tad bigger than the 15, by one inch. The old Singers make beautiful stitches and are really rather fun to FMQ on.