This is yet another product like SprintBooster described here
pretty well and in satisfactory (non-worry warranty) use by several folks on this forum including me. I also use a similar but more variable (like e-Drive) product called a Pedalbox on my R8. I am fully satisfied with the installation and utility of the Sprintbooster on my Q3 though the R8 does in fact benefit more from the added variability of the Pedalbox.
These devices simply plug into the throttle connector of the car (hence no warranty issues as they are fully reversible and discreet to the CAN) and alter or modify acceleration signals between your foot - the physical pedal - and the car, in a different, modifiable way.
I will caution on two points though - First, they cannot and do NOT add power. This is simply not possible with a throttle-modifying device. What it DOES do is change the relationship between your pedal position and the corresponding signal to the car's electronic throttle. This is a ZERO SUM function though - that is, if you add more throttle sooner in the pedal travel you MUST therefore add less later, so if the slope of acceleration of the pedal input is higher (faster) in the beginning, it MUST be flatter (slower) later to reach the same point - look at the reference curves in the first post direct. Thus, NO additional power is ever created. BUT, the throttle sensitivity is GREATLY enhanced AND THIS gives you the driver a different experience, often yielding the FEELING of more power. btw, this is a usual technique of all automakers to adjust their car's drivability and is the first thing that "sport" buttons also do to some degree. These devices just capitalize and enhance that function. Many folks would say, just step down further on the loud pedal to get the same effect - true, that's rational but in practice IT is different. Your foot feedback relative to pedal travel is a psychological input and just using more travel to get more throttle is affected by the slope of the curve that these devices modify - hence a different input and feeling for/from it.
Second, I would NOT expect a change in fuel economy with these devices as their function actually encourages faster starts and usually LESS economy - which is why they aren't programmed this aggressively in the first place. BUT, I have NOT noticed a variance in MY own fuel use with the device - prolly cuz I spent most of my time with the foot to the floor anyway ;-)
So if increased throttle sensitivity to foot travel gives you the feeling of more acceleration aggression and 'power' is your primary intent, try it - you'll prolly love it as I do my Sprintbooster and Pedalbox, but if increased fuel economy is your primary driver, don't as you'll likely be disappointed and therefore unhappy with the choice...