Exactly +1I use s3 almost exclusively.
Start the engine, push the button once to get into D and again to switch to s3.
Start rolling and witch traction control to level 2 (2 bars) if wet, otherwise to level 1, and enjoy.
I hardly ever use the manual mode. Always in Auto and I force up or down, as needed, using the +/- buttons. Works excellent even riding some very rough Jeep trails available locally.
For long stretches of tarmac S1, S2, S3 & D will all put the bike into 6th gear and you will get identical gas mileage. In fact the difference in gas mileage between S1 & D is absolutely minuscule compared to the difference in gas mileage due to how you use the throttle and the speed you ride at.D gives the best gas mileage, and for long stretches of tarmac I din't see any reason to burn for gas.