I find the dynamic range of the S sensor to be all that I really need, I couldn’t really quantify it because I don’t believe that measurement ever really means anything. I will say that I don’t have any difficulty recovering highlights that are 2+ stops over exposed, but I rarely attempt to recover extremely deep shadows because that’s always where noise lives on any sensor.
When it comes to the dynamic range of any sensor, it’s important to me not because I want to recover improperly exposed images, but to extract as much detail as possible out of my properly exposed files. In those scenarios I often find that I can process my S raw files multiple times to create an extended dynamic range image from just one file.
And it’s not hard to upgrade your S camera…just sell it and buy the next one! It’s the same thing users of other systems do when new bodies and backs come out.