Hi dslavin. The next vehicle I make, I am trying your method.
The orginal body was started in ShadowBox (when it first came out, I wanted to test it). After I got a base shape for my vehicle (a 32 highboy), I then cut away to make it closer to the shape of a 32. After that, I did use a TON of Hpolish. Man, I was really hoping you wouldn't say you retopoed-

See, guess I am just trying to find away where I can sculpt, 'extract/retopo' a new shape (quickly), then reproject the details back and have the body real SMOOTH but, with a low poly count as well. Thought QRemesher was going to help, but, seems my model (tool is so high in poly's, that it's locking up QRemesher). The next step I was going to try was the new retopo brush and see how that goes (if it's easier than retopoing using the method you just mentioned).
So, looking to try the new retopo brush (as just mentioned) and try your method of working up, Hpolish, work up, Hpolish, and see which one is easier.
What do you think?
Sorry, just that I find retopoing with a sphere such a pain (I did try it once and just wanted to put my fist through the computer-

... just kidding, but I really did not like it).