I bought this Active Valve Control last week https://www.active-sound.eu/en/audi/audi-a3/audi-a3-8v/active-valve-control for my PFL RS3 and altough very expensive for what it is, I am happy with the result. I noticed that with the stock software the valves always opened on every start up and then close immediately, resulting in very loud starts, when cold and when hot (as most of you know). I really liked then noise, but the RS3 is my daily and I get up early so it was annoying for the people around me and even at my work. With these valve control the valves (in comfort mode) stay always closed during start ups, so cold and warm start ups are much more silent, it is a huge difference. The other positive part of this valve control system is that in Dynamic mode the valves are always open, and not only after 3500RPM as before, so I get to enjoy the sound (and the pops and bangs) at lower speeds and lower RPM. As long as this system is reliable I recommend it 100%!