Crickets.... crickets... lol

I have found most multi-site folks out there are pretty proprietary about their setups. I imagine it may be less likely for them to comment publicly because of that.

I considered that, but still... it's open source software, there's got to be someone with experience who is willing to share.

I know this is old but Updates to the core or updates with the database?

For Just Basic Core: Centralizing the core should handle that. That way you are dealing with only 1 install for all sites connected to that install.

For updates that require each install to run the update script including Database changes simply create a cron script to run all the update for all the sites you want with that one script.