Ok, I'm officially a dyntopo fan. I think I'll presculpt all the characters with this prior to retopology. I'm at the point where I need lots of peripheral characters and background people. Here's a secondary professor sculpt I pounded out in about an hour or less.
So I finished a new version of my texture paint script that works in concert with agisoft photoscan. This is a screen grab of a trash can I scanned in retopoed and used the script to upgrade the texture. If anyone wants the details of the work flow I can post it up, but I think I've got it down well enough to start churning out the props.