Well my gas mileage isn't that bad using the Sprint Booster. I lost about 2-3 mpg from my usual 22-25 mpg city driving.

I think I might be getting use to driving the car now with the SB, but I had to reset the throttle a bunch of times after every trip in the car. It now feels a bit more tolerable after the throttle resets. Doing so has given me a little more pedal travel (about 2" now) and some dampening for my foot.
It really sucks when your in 1st gear and you drive over a little bump or dip in the road, your foot lightly taps the throttle and whoooaa look out!!!