Being an ASE certified technician is worth something. I respect that.
I'm not an ASE certified technician but I'm not some uninformed dufus spouting crap, I completely understand how the Sprint booster works and what it does.
I agree that if I installed a Sprint Booster the interface between pedal and throttle blade would be different, more responsive.
I know what throttle response is and what it should be, how a car should feel. I also know what a hesitation or lag is in a Crossfire or other car. It's an annoying drivability issue that people take cars into a dealerships or independent shops to get fixed quite often.
My car does not have any built in hesitation or lag. It does not have any hesitation or lag attributable to wear and tear conditions or non maintenance or the like.
My has just over 40,000 miles on, and is a well maintained Spring-Summer-Fall only car. It has summer (3 season tires) It will be in the garage in just a few weeks.

Why did you do injectors on the car?, it must have pretty high mileage to actually need new injectors. I'm sure the results were good if you did injectors, intake (which I'm assuming is a CAI to replace the engine top box) and tune done all at the same time.
You also have no evidence proving which of the components or the tune, cured any legitimate drivability issue that may have been present on the car initially.
We can assume it was the Sprint Booster.