The S-AFC has 8 indiviual rpm settings (you choose) & interpolates between them.
It also has a high & low throttle setting feature & interpolates between them as well. (WOT - Part throttle - You pick the Throttle %'s too)
All digital accuracy! (not analog dials/pots - ever heard a scratchy volume knob on a radio - How do you know "exactly" what volume level it's at too?)