Fibersport,
"... is the 4th motor I've bought chasing what I was looking for in a servo motor."...
...is exactly the dilemma most buyers face when not having the opportunity to test a unit, in our own applications, before purchase, myself included. After lots of research, I purchased my 1000SH models because they were the only motors I found that met multiple requirements, the most important being a wide range of speed adjustment with high torque at very low speeds without the need for speed reducers. I can sew 1/2" of veg tanned leather with ease and complete control at a regulated 2 stitches per second, when an error, a misplaced stitch, produces instant, expensive scrap. Or, I can sew three layers of heavy canvas as fast as I can get my Singer 7-33 to run, all with the same motor, and with the push of a button on the control unit conveniently placed within view and reach of my seated position. Thanks to another sewing forum member, like you, for having posting their story of sorting-out the best motor for them, I learned about the Kinedyne product line (and Ryan Neel.)
And thanks to our moderators as well.