manual mode everyday, rain or shine, track or daily.
I like being in control, but I'm not stupid enough to justify taking loss on my car, and then putting myself through hell to find the manual version of my car.
It is a discernible difference between driving in just "drive". It feels like better power delivery. Less work on the trans in my opinion too. less thinking, "okay, fully engange throttle now? or halfway anticipate driver might begin to brake soon" type scenarios.