Older Pfaff with vertical bobbin and PQ 1500. I measured the guide lines on the Pfaff when I bought it, they are spot on, so tape is good. If you want to piece rapidly, Pfaff does have a single stitch foot plate. For any other stitches, like a zigzag or blanket stitch for binding, I use the open toe foot. The one drawback to the 2100 series is no mechanical adjustment for foot pressure. That's where the 1500 outshines the Pfaff.
I've owned other machines - but for years, starting with the 1471 I had, only Pfaff let you do your own stitches. I'm not limited to what is on the machine.