I am running one in my 12th scale and have ran it in my sedan.....it is a very good speed control and I would buy another one over my Quantum any day. Seems really punchy and faster overall...... The resistance rating is the lowest I've ever seen as well....... .00025, as well as no motor limit.
Service is very good too, my sx9 went bad ant they replaced it with the sx12 for free........Horizon Hobbies is the importer for GM, so its pretty easy to get it serviced.
Chris