I went to Heather's workshop last September, at which time I blogged:
Definitely a challenging practice for me, since I am not quite so flexible and fluid, but not so energetic and aerobic as some. Less sweat, more surrender and and some new concepts - Yin yoga, which is sort of a surrendering, not hot, do not force breath into ones body kind of practice. Apparently wonderful for loosening up the connective tissue. It was an evening of curiousity. And humility.
So it should be interesting to see how that changes - I am a much stronger and practiced yogi a year later but also I remain challenged by weight and flexibility.