Just got my APR stage 1 tune installed on my 2018 RS3 saloon yesterday and wanted to share my thoughts/hear those of others who have gotten the tune. I live in Chicago, Illinois where 93 octane is at every gas station. We also have plenty stations that sell E85. I elected to have the map switching capabilities and programmed them as follows. Map 1 : 93 Octane (primary map for me) Map 2 : 91 Octane Map 3 : E85 <--Can't wait to fill her up with this. Map 4 : Stock PERFORMANCE Very noticeable increase in the vehicles performance. The throttle becomes a lot more responsive with less lag when pressing the peddle. The car pulls hard and just keeps pulling. I am very impressed. As if the car wasn't hard enough to drive calmly before, it is now that much more difficult. I just want to plant the peddle to the floor over and over. SOUND I was a little disappointed in this category. I feel like the noise from the exhaust is just a bit more tame. The crackle and pops seem to have decreased maybe 20%. This is noticeable upon start up and most of all when the car downshifts from 3rd to 2nd gear. That back-pressure sound you get pushing out the exhaust at 2,000 RPM when the car downshifts was a thing of beauty. For those who own this vehicle should know exactly what I am talking about. That 3rd to 2nd downshift noise for me is noticeably quieter. I am not sure what caused this, but my GUESS would be the fuel burning more efficiently now that the ECU has been tuned. If I am correct, I would think this is a positive thing as far as performance goes, just not for the sound that we all crave. Overall I am very happy I got the tune done and already looking forward to leaving work and driving this beast. Just wish I could INCREASE the noise level but do not want to get rid of my factory sport exhaust.