I have no disagreements with any of the ideas presented so far, with Medical being my favorite and splitting Wilderness and Urban being my second favorite.
Having said that, I find this forum the easiest to read of the few I follow regularly because there aren't four dozen 'main' sections. So I guess my main suggestion would be to keep any changes simple.
You and Chris have done a great job with this site and I'm looking forward to whatever you come up with. Good luck!
FWIW,
Chris.