The main selling point for the Sci-Winder is that it only needs 1.8" of space below the top surface of your panel.
The Sci-Winder was developed to be a compact, high-end spinner with a super-clean look on the knob (no set screw holes). The included large, solid stainless steel, anti-theft knob is also one of the main selling points. The knob will (or can be made to) look the same as it did when purchased, after 30 years in a commercial environment with 24/7 use. The weight of the knob was tuned to give it the same solid feel and play dynamic as a standard TT2 with
both the "Premium Aluminum" knob and ESC options. But it is intended for those who are more interested in simply having the best spinner possible, than those who are looking for the versatility of different knobs, steering wheels, etc.
The main selling point of the Turbo-Twist line is true (costly) industrial optical encoders, better than even those used in the arcades. Inexpensive Hall effect sensors can introduce lag and accuracy issues and aren't really the correct technology for the job. But for something like an A1UP, where the control settings for a given game may not even be correct, few of those users would probably notice.
It all depends on user expectations and their budget.
On a side note: Glenn and his Chinese buddies are pretty brazen copying my original spinner body and High-Low knob designs nearly verbatim! But again, looking the same and playing the same are two different things