here are the pics I took of the difference in height of the fmq foot that came with my PQ1500, and the 2 I bought that seem to actually work for the machine..
The 1 on the left in each pic is the original foot, you can see how much taller it is, how much higher the upper bar is. I think this is why I had the whp (weird hollow pop) noise and so many needles breaking, thread breakage, and awful stitches with the original foot; made for a terrible fmq experience. Even with the presser foot pressure adjusted all the way down, the original foot just doesn't work.
I know several of you asked about this, so hope it helps you. I have used both of the other 2 feet, and they both are working great!
Left is original, right is new one that works
Left is original, right is the new one that works