im a little confused here,
are you on a poly budget? u have a max poly count u dont want to reach?

why are you relying on maya's subD do try and get a god shape with as little geometry as posssibe [it seems to me..]
also, i think the fet need a lot more work.
especially the ball of the feet and the toes.
the thing about using refs to model is that u can rely too much on a photograph, theres so many factors that can make a shape look good on a 2d picture but slightly outshape in 3d.
take that into consideration.

also, you should just add geometry where you need to get more convincing shapes and where you need to keep mass.
i know this may be your "technique" of modeling, but your models could get a lot of boost if you just add geometry as you need. get creases to crease more, and bulges to bulge more etc...