I really hate that function I always deactivate it in my car. You can maybe call me old fashioned but I think in al long term is no good for the car. Maybe you can save some money on gas, but I think that the battery and the ignition parts will f..ck off sooner. I also feel stressed (a mental thing) when the car goes off in the middle of the journey, no matters that it´s stopped I feel a kind of uncomfortable.
I suppose I´m not a futuristic green person