Ok, so have some good news.

There definitely was something wrong with the upgraded VM.  I built a new one from scratch (thanks @Technogeezer for the ISO script), and installed the tools.

The Steam install of DA:O worked just fine.  I'm able to launch and play the game - the visual artifacts are gone.  

Trying to resume my old game copied from the other VM fails if the texture detail is on high, but works on medium.  Starting a new game from scratch works with details on high.  Changing from 1920x1200 to 3480x1260 crashes the game.

So I suspect that the new tools install isn't removing the v13 video driver properly.  Doing an uninstall and reinstall didn't fix it in the first VM.  @Mikero does that make sense?

There's still some instability in the video drivers from the crashes above, but it's basically butter smooth at 1920x1200.

Net:  My recommendation is to build a new Windows VM rather than upgrading an old one.  I'm going to replace the others I built off a copy of this new fresh base version.