Great report! I'm moving to WI soon and now they move Oktoberfest to the west coast. I can't win! A Laguna Seca event would be phenomonal!
I think when you say technical, you have to consider corners AND elevation changes. I think elevation changes really adds the challenge. It sounds like Mid-Ohio has plenty of both!
Understeer. Your assessment matches what I've experienced. A lot of people bitch about how the E9X M3 has lost its soul and blah, blah, blah. I'll say this...if the E30 M3 defines what an M3 is because it was neutral and high revving then the E9X is the closest thing because it is the highest revving AND the only recent BMW that doesn't go into terminal understeer in stock form when pushed.
2015 F34 328iX GT Glacier Silver
2011 E90 M3 Monte Carlo Blue
2004 E46 M3 Imola Red