hey, I'm technical all day.
here I can call it a weird pokey thing and feel confident that you all knew what I was talking about... heehee
I'd say to get one that fits (low shank) but feel comfortable that you can adjust it as YOU need to according to your FMQ style. I was enjoying a FMQ blog site and she really encouraged us to embrace the thing for what it is - a tool. Adjust it as you need to. Stick something in it to adjust/reduce the tension against the fabric too if you want. ;-) That really helped me open that FMQ up so I could move as I needed to...
The $3 foot is much better than the no foot attachment set up with the New Home machine I have.