[gkhn]

The work van has this.
I don't like it. It adds 1-2 seconds of delay.
Makes me really nervous - is it going to start this time?
Luckily you can disable it or you don't push the brake pedal all the way so it doesn't activate.
The amount of fuel you are going to save is minuscule.
Probably the starter motor and engine will wear out faster too when you frequently start/stop.
But who really cares..
They make them cheaper and doesn't really matter if the car fails. If it can make it till the warranty period is all that matters.
They just sell another new one