Ran it through Coder, fixed a few queries, and implemented it using at the theme layer using these instructions http://www.apaddedcell.com/an-introduction-user-stats-module-drupal.
Works for my needs. I never used this module in D6 so I'm not sure how some of this is supposed to work. I'll apply patches, but I'm not going to respond to support requests or bug reports without a patch.
The sandbox version of this module should be pulled back into the user_stats project.
Let me be 100% clear. While this version is being used on a production site, it is with a very limited configuration. My goal in sharing the update in my sandbox was to save @Liam McDermott or another developer some time.