When I installed mine, I checked to see what sort of range on the throttle it gave me.
At fully closed, the TPS reads 13.3%. At fully open it reads 74.5%.
With my cable shifter attached to the throttle, I was able to go anywhere from 13.3% up to about 54% before the shifter maxed out. So I have about 2/3 of the throttle range covered.
Each click was about 2% throttle or so. And even between clicks I could set it to within about a half percent of a given target. Actually better than I could do with the pedal alone.
I'd be interested to see the numeric range someone gets from mounting it to the pedal.