I have that same model and they work great! Programming is really easy!
It's actually harder to find out the actual speed discrepancy, in my opinion...I hate having to hold my hand steady on the throttle, glance at the GPS, glance at the speedo, then glance again at the GPS, back-and-forth until I'm positive I got the right numbers...but I'm anal, so...
Oh, if you're using a GPS to get your calibration numbers, I recall it's best to use a speed of around 40-50 mph to get the best average, as your speedo will always be off at some speed no matter how much you calibrate it with the healer.
Good luck with the sale of a great product!