I have been driving Volts since February 2011. I currently have a 2014 Volt and a 2015 S.
I loved the Volts, and still do. The entire driving and ownership experience is far better than any of my previous cars. I love driving electric, and I only use the ICE range extender for regional trips. Today it is 10 degrees F outside, so I use a resistor to make my outside air temperature sensor read high, defeating the dreaded ERDTT.
The S replaced my V6/6-speed automatic ICE car for use on long road trip vacations. It is superb at the task and it loves to be on the freeway, five over the limit, autopilot engaged. I plan my route and charge to 100% overnight. My normal stops for food or restrooms are more than the car needs for supercharging. It is a great experience.
I still drive both cars, but I much prefer driving the S. The Volt is smooth, and always has adequate acceleration or better. The S also is silky smooth, and accelerates like a Corvette, nicely enhancing the driving experience. I have a plain 85D, the Performance or Ludicrous options would be a waste for me.
I love the streaming media in the S. Podcasts, internet radio, name any song and the car will play it, etc. I also love the easy google destination entry to the Nav system, the big google map, and the detailed Navigon maps on the IC. I love the heated steering wheel, and I love having way more battery energy than I need around town. Crank up the heat, take the interstate, drive fast. I do not even have to bother to look at range remaining. The S is truly exceptional, better than the best, and by a wide margin.
One thing I do miss in the S, as mentioned by several others upthread, is "charge based on departure time." That would make it easier to leave in the morning with a battery that has been warmed by charging, and to schedule those 100% overnight charges before a trip to end shortly before I leave.
GSP