his retopo bit on the head would have been massacred with just two lines of gpencil and using the bsurfaces but of course he’s taking his time talking and explaining. i have watched all retopo softwares in youtube and believe blender to be the fastest, with a little python know how you can bundle inherent commands to in a single button to save time.
shrinkwrap in sculpt mode can be active by going to options, by the way shrinkwrap update works even in sculpt mode, thats why the polysculpt button is there so you can grab and smooth the mesh and then activating shrinkwrap update to conform the mesh to the sculpt surface again. the disadvantage of using an active shrinkwrap in sculpt mode is that what you are seeing is a projected result of the modifier not the actual placement of the vertices in “real” space. that is why some heavily distorted areas while they may look fine in an active SW one tweak of a vertex and it may cause heavy disturbance of vertex positions in its vicinity. one of the reasons why i made the macro command.
with the constant progress of the Contour tools, and if its fully matured and released along with the development of the GSOC 2014 quad remesh (autoretopology), most of these other retop software would cease to matter, that is of course if your mainly blender.
we would be offered with a much more stable workflow = dyntopology for prototyping, autopo for continued sculpting in multires and finally contours for production topology.