Have you driven one?
I drove a Chevrolet Impala with GM's start-stop and found it to be fine. It monitors brake pedal pressure (it isn't just a switch) and even if you want to creep forward, it has the engine running timed very closely with when the engine would be overcoming the brakes. If you want to start off quickly, it's running in less than the time it normally takes to get your foot off the brake and onto the accelerator. Cold start and warm up, it leaves the engine running. A/C demand, it monitors how much and either leaves the engine running or allows a short stoppage and restarts it when there is cooling demand. Turn signal flashing (indicative that you might want to do a quick restart), leaves the engine running.
Try it. I don't recall finding a realistic scenario that would catch it out.