Just got the APR Stage 1 ECU Tune for my 2018 Audi S3. (High Torque version) Huge difference, but have kept it light on the gas pedal since, due to APR not having the TCU Tune available for my car yet since it is so new. They have DQ250S S Tronic available, but I need the newer APR D2381. So apparently the ECU upgrade can cause some clutch slippage if not done with the TCU as well. No ETA on the TCU - there working on it I was told, so I check there website daily for the new update.
https://www.goapr.com/products/index.php?v=A3&vg=3 My S3 was fast, but very noticable difference with the ECU Tune. Definitely pleased with the upgrade. Hopefully the TCU Tune will come very soon.
APR Local shop : ECU Tune $859, and TCU Tune $760