Yeah, I use the smooth Proxy all the time when doing anything organic, or that has smooth curves etc.
One other tool that I use a lot is the sculpt poly tool on the low poly model, really lets you get some good starts for muscle definitions (as long as the topologys there from the start) Alsot if you've got some uneven geometry the smooth brush can really help you out, you can have auto smooth on the push and pull brushes too.
"No pressure, no diamonds" Thomas Carlyle