Well, I have the "stitch regulator" -- and I'm one of the ones that has been posting most recently on the Bailey Yahoo Group about having troubles with it! IMO, it is not truly a stitch regulator; I had a stitch regulator on my Juki, and it worked as expected -- when you moved faster or slower, the regulator would adjust as well, and your stitches would stay uniform.
My Bailey stitch regulator doesn't seem to do that; my stitches adjust in size based on how fast I'm going, which is not good. I've spoken to Mr. Bailey about it, and he's sending me a replacement (which will hopefully arrive soon). I'll post back here once I've gotten it, and let you know if I see any difference. I would really like for the regulator to work as expected!