I've never really had a major problem with the throttle response on the car. Maybe its because I tend to apply the throttle smoothly and progressively as the car accelerates, rather than just 'flooring it' and waiting for everything to catch up. Yes, it can be a bit sluggish when synchronizing revs during down changes but not a big problem. I find the best technique is to blip the throttle above the desired revs, with the side of my foot whilst 'heel and toeing', then let in the clutch at the desired point as the revs fall. I always find there is enough time to perform the down change within the braking distance. I can't say I have ever had to push the pedal to the floor either.

Despite the glowing reports regarding the Sprint Booster I've not actually bought one as I always felt it was just yet another layer of complication on top of the drive-by-wire system; one algorithm fighting another, and as stated I don't have a big issue with the standard setup anyway.
But rather than dismiss it completely, and the fact that I have sneaky idea of what little there is inside the Sprint Booster I decided to have a go at making my own, but with the added feature of having 3 selectable response curves; standard and two custom maps. So far I have removed the pedal assembly and confirmed the two sensor outputs as being completely linear. I then built up a processor board to take the sensor signals and provide two outputs to feed back to the ECU as the modified pedal signals. I've now got some code running that allows me to upload (via serial link on Zterm etc) 2 maps and select them or the original liner map with switches. The maps are only 16 point at present which may be too coarse but this can be changed, possibly giving more resolution over the first portion of pedal travel. Its running great...on my bench. I will be trying it out for real at the week end. The installation won't be as slick as the SB since I haven't been able to source the AMP connector yet and will be a lot small than my test rig!