Hi Kristen - we painfully moved at the end of the summer. For the most part the Admin Console migration was not too bad, it was when we moved to the Unified Experience we started to see some issues with our instance. One of the biggest draw back is also something Stacey mentioned was the management of 3rd parties and contributors. You have to move everyone regardless of what their role is. We have an issue because we have our 3rd parties as resources but our team leads and project managers update their task. We can no longer have them as a Resource as each Resource needs to have a valid email address.
We do not use SSO either, so there was very little for our IT to do other than make sure the sites were Whitelisted (which should already be completed). But the web address changes slightly once the conversion is complete.
Managing users is not too challenging, but make sure your Sys Admins have the correct rights. The Admin Console is not very intuitive when making sure your Sys Admins have the correct rights to all environments.
My only word of caution, is do not rely on your Adobe support team that has contacted you to help you out. We found them to be very pushy and not very much help. Fortunately, I was able to figure most of it out myself. Keep your Account Manager in the loop on all emails - this helps manage the cut over expectations.
Good luck in your migration - feel free to reach out if you have any other questions.
