Know some folk in areas where traffic to work is a crawling queue and they turn off their stop start partly because they dont trust it, partly because they dont like changing their driving habit, and partly because they know people who have had to have new starter motor under cars guarantee.
Engine stop/start systems do not save fuel, but it does reduce poluution, especially in urban areas where there can be a lot of vehicle activity. The vehicles have different starting systems to older vehicles to cope with the extra demand which include a higher capacity battery and it is also essential that the higher quality synthetc oils specified are used when the vehicle is serviced. There are a multitude of conditions that need to be met before the engine stop/start sequence even kicks in, including:
1) Engine must be at a minimum temperature.
2) Heating/Aircon in vehicle is at desired temperature.
3) Battery is at a minimum charge level.
4) The front wheels are pointing straight ahead
5) You have not stopped on a hill
6) If diesel vehicle and DPF fitted it is not on a regen cycle.
Only then will the engine stop when the vehicle stops on a journey.
In winter on a short runs the stop/start sytem may not activate at all.
Not heard of anyone with a stop/start vehicle having the starter system changed due to wear & tear, but have heard of many drivers having their older conventional starter changed as it had worn out.
Have had 2 vehicles with start/stop systems over 150,000 miles/7 years and never had a battery, starter or engine related problem due to start/stop.
Even Honest John agrees.https://www.honestjohn.co.uk/askhj/answer/52165/will-a-stop-start-system-wear-out-the-starter-motor-