I have a Brother PQ 1500s with a top speed of 1500 stitches. Way too fast for me, but like others have mentioned, I had trouble keeping the speed constant. So I taped a few layers of thick cardboard between the pedal and base to act as a governor. It took some trial and error, but I found my sweet spot. This way I can mash the pedal all the way down and the machine runs at medium-high speed. I thought in time I would remove some of layers of cardboard and up my speed, but when I try that my stitching gets messy, so I just go back to what I'm comfortable with.