USUALLY my custom mode, which is 100% torque, 100% regen and 100% braking regen. When I'm on the back roads I seldom touch my brakes at all, just use the motor regen to slow. On the highway I use "ECO" as a "Poor Man's Cruise Control." I go into a full tuck and just hold the "throttle" open to cruise along at 70mph. Even though the posted speed limit where I live is only 55mph, the police don't bother you unless you're going over 70, so...
Once I'm off the highway I pop right back into Custom mode. I don't use "Sport" at all.