The idea that Sean "controlled" the music and projection was just that--an
idea, an illusion propagated by his immense skill and wonderful sense of
timing. The advantage to using sensing system is that the control would be
real, not contrived, and would expand the palette of sound available to the
dancer. It is certainly not for everyone--most dancers, I imagine, are much
more comfortable being told what steps to do, when to do them, and then
shine the brighter on the stage. Whether set or no, in a sensing
environment the timing would always be (assuming the equipment functioned
correctly) right on the money, and performances as magical as Sean's would
be more the norm, rather than the exception.
Idealistic, aren't I?