My cars are too old to have the start/stop system but I've experienced it in rental cars and my immediate reaction is that I don't like it - especially the lag between when you move your foot from the brake pedal to when the engine actually starts running.
It wasn't so bad with a manual transmission (~2016 Mini Cooper) as I often start to ease off of the brake pedal as I start to depress the clutch, so once it's time to give it some gas, the engine is probably running.
That lag felt extremely annoying and potentially dangerous in an automatic ~2018 Volvo S90 though. Maybe I move my feet faster than the average person, but if I quickly moved my foot from the brake to the gas, the car would just sit there for a split second ... wait for the engine to start ... and then start moving. I know it's a low probability, but I definitely felt as though that car would give me a lesser chance of a making a successful evasive maneuver if, say, I noticed an out-of-control vehicle hurtling towards me.
My newer car has features to help offset this, including brake assist or whatever fancy name they call the feature. Remove foot from brake pedal, engine starts. The key is that it stays in neutral and the brakes remain applied until you hit the gas. You just have to get in the habit of removing your foot from the brake that split second earlier so the engine is running and ready when you want it.
This is how I feel about it as well, although if I think about how slow my current old car accelerates maybe it's not enough of a difference to matter.
It wasn't so bad with a manual transmission (~2016 Mini Cooper) as I often start to ease off of the brake pedal as I start to depress the clutch, so once it's time to give it some gas, the engine is probably running.
That lag felt extremely annoying and potentially dangerous in an automatic ~2018 Volvo S90 though. Maybe I move my feet faster than the average person, but if I quickly moved my foot from the brake to the gas, the car would just sit there for a split second ... wait for the engine to start ... and then start moving. I know it's a low probability, but I definitely felt as though that car would give me a lesser chance of a making a successful evasive maneuver if, say, I noticed an out-of-control vehicle hurtling towards me.