Not sure if this applies here or not, but some people have confused the Cruise Control (or Speed Control) with a stitch regulator. Actually, the name describes what the function is. A Cruise Control does not regulate the stitches and I don't think the Stitch regulator controls the speed. In this case maybe it does. It is helpful to understand exactly what a person is asking.
I have a Bailey with their Cruise Control which I think is very good. I have not had the urge to have a stitch regulator although I have had people ask if the Cruise Control does that. In my case, it does not. You need to learn how to move the machine in time with the rythem of the needle and the stitching. I am not bothered by stitches that vary in length. I am not a perfectionist, so I don't worry about that.