An hour ago I migrated from a C-5 hub to a new C-8. No issues, and an experience so smooth it was almost boring. The migration instructions say to disable lan and cloud integrations. I didn't know what that meant. There is no Disable checkbox for a Google Home integration, IFTTT, or Sharptools. So I didn't do anything with them, just migrated, and then went to Google Home app and the IFTTT website and re-authorized. Then used the Sharptools migration tool. Easy peasy.
The reason I migrated was because the C-8 has external antennae and I was hoping it would solve my problems connecting to battery devices (locks) at the edge of my network. Yes it did, in a big way. Previously I had to use Aeotec range extenders and still had so-so feedback (commands usually executed but locked/unlocked status often didn't). Now with the C-8 hub I no longer need the Aeotecs and feedback is almost instant.
So yeah, big thumbs up here.
You may want to re-phrase your praise if you want to appear on the testimonials on the Hubitat web-site 
Great to hear you had such an easy transition to a C-8
Here is how you disable apps for future reference: Apps Page | Hubitat Documentation
The reason that was in there is they found some people had so many LAN/Wifi integrations that needed to be re-authorized, by having everything enabled it was causing so much web traffic trying to connect to servers over and over it would crash the hub. Sounds like you had a small number so it was not an issue.
Thank you for your kind words. I am glad your experience was "boring". That was our goal ...
I see that @jtp10181 beat me to it... Was just about to say that you need to activate the "disable" checkbox, first. Every app on Apps page and every device on Devices page can be disabled:
Some of us have a pretty low boredom threshold.... Not sure you reached that for everyone.... You'll need to try harder next time... 
