Does IS help with slow moving subjects?

The question was: "Would there be a benefit from using a stabilised lens versus a non-stabilised lens?"

The answer is yes.  I drop my exposure time down to a plodding speed sometimes because I'm working in very dim lighting conditions, and the results from having the IS active are significantly better because my viewfinder is stable and because the only motion that I have to deal with is the person being photographed.  Vibrations from my interaction and the shutter and mirror moving are countered by the image stabilisation.  IS also makes things much easier when I'm working with manual focusing and trying to adjust the exposure settings to compensate for changing lighting conditions.  IS is also useful when the camera is mounted on a tripod, as it counters the residual vibrations as a result of those same inputs, although that has become less of a problem now that I got a better tripod that is made of something other than aluminium.  IS is almost always going to help return a better and more consistent result.

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http://www.alexanderrogge.net/arshutterbug