We recently picked up a Jeep Cherokee with the Stop/start feature. I've worked on the systems a little bit, so I knew what to expect and helped my wife acclimate to it. We are by no means hypermilers. Observations:
1. She got used to it pretty quickly. She even started to pay attention to creeping at a light, which would turn the engine back on. now she tries to hold her place and let the engine stay off longer. Like I said, in no way a hypermiler, but now she is paying attention and trying a little bit to get better mileage.
2. The A/C does degrade a bit when the engine is off, but the engine will turn on to keep things cool. It will still allow 20-30 seconds of engine off time in 90 degree heat.
3. Ours has a trigger speed of ~5mph, so we have to drive over 5 mph for it to re-stop. That way in stop-n-go traffic it doesn't drive the normal customer crazy. yes it may drive an ecomodder crazy. you're not normal
4. For whatever reason, it stopped working for a couple days. I know it requires a certain battery voltage/charge before it will start working, so who knows, maybe something drained the battery a little extra that day. Anyway, we were annoyed! This is a feature on my new car dang it, it better work!
It did start stopping again.
5. Throttle response is pretty good, and even if you are worried about response (like turning left in traffic) you can always lift of the brake a little bit and it starts up, ready to go.