I thought I'd give a short update on my migration from the old C-8 to the new C-8 Pro. It was mostly uneventful, but since I don't do this for a living or have my life revolve around tech stuff, I mostly had trouble getting the various pieces of the Hubitat environment to forget the old device and allow the newbie to take control. It was a several step process to remove all of the C-8's fingerprints, so to speak. It mostly works OK. Seems to be a bit faster, but occasionally it still hiccups on one or two of my automations. The only frustrating thing so far, and one for which I would like some opinions on, is as follows. After the migration, I added back a Leviton DZ15S switch that I had disabled because of it being a bit flaky. It got added to the Pro easily and I can control it fine from the Hubitat side, but even though I have seemingly added it to the Google Home app in the HE interface, the Google Home side hasn't recognized it yet and it's been several days. Any ideas?
You could try going into the Google Home app and go through the Works with Google flow again and do a reconnect with the hub.
I think I already tried that, but may try again.
I was sceptical, until I tried it. The snappiness of the web interface and the responsiveness of every single rule firing is definitely worth it alone. Life's too short to be waiting around for screens to load up.
@danabw "Something went wrong. Try Again" I got this message at the end of two different ways of attacking it. First when using the "Check for New Devices", and then the second try with "Unlink" and then relinking. Now I wonder if I have any linkage at all. Now Hubitat does not show as Linked, whereas before it showed Hubitat as linked but I couldn't get the latest Leviton switch that I re-installed to show in Google Home. Now I have got myself in a pickle. I don't know why it's failing the link.
Perhaps I need to de-install and re-install the Hubitat Google Home app?
I notice that the Google Home Hubitat app no longer shows in the Built-In apps (or did it ever). There is a Google Home Installation Helper. Perhaps the Google Home app is found elsewhere. Anyway, after unlinking and removing both the Google Home related apps, I re-installed the Google Home Installation Helper and went through its steps. Got the same "something is wrong" message.
The Google Home integration has been wonky for me over time...seems like most of the time it's been a Google issue as it's stopped/started working w/zero changes on my hub.
I'd restart your phone, and reconfirm that your Hub isn't listed as an active device in the Works w/Google list. Remove the Google Home app from your hub if it's been installed (should be installed when you enable your hub via Works w/Google). Then start over authorizing your hub in the Google Home app and just select one or two devices initially to authorize, including the Leviton switch (you can do the rest in the HE Google Home app after the initial set up). Confirm that's working then add additional devices.
@danabw See my added paragraph about the Google Home related apps.
The HE Google Home app is automatically installed after you enable your hub in the Google Home app on your phone. So you won't see it in the list of built-in apps AFAIK.
I'm not sure how what you can do to help w/the "Something is wrong" message from the Google Home app when you're adding the hub via the "Works w/Google" process on your phone.
There was a long topic here recently related to problems getting the GH integration to work and it wasn't resolved until the person contacted Google support and they did something on their end...maybe search here for somewhat recent (last few weeks?) topics about "Google Home."
Oh, you also could/should try clearing cache on the GH app on your phone and rebooting phone before trying again.
Found the previous topic about GH issues...not the same issue as yours, but could be helpful, start at the post below in the topic, summarizes things tried/success:
I finally got the Google-HE Integration to work after 3-4 failed attempts. Removed all links from sides, several reboots, and also paring down the number of devices I really wanted to integrate. Thanks for all the device.
Glad to hear it! 
I just got me an O-Droid from Ameridroid to fool round with and see what I could do in Home Assistant. I worked with it for about two evenings and decided that I am finally at that stage of my life where technology is finally getting out front of me, and I need to just settle in with the easy-to-do.
So, C-8 and Rule Machine, or simple rules for this old man. I will absorb the restock charge, lick my wounds, and move on.
Still getting random stuff coming on now and then but I turned on that feature where if a state is not returned it will keep trying. -sigh-
I got curious about differences between the C-8 and the Pro. I see now that the 8 isn't even offered and the Pro is less money by far than I paid for my 8 non-Pro.
Something tells me if I spring for a Pro... the 9 or something more will be released within weeks.
Please hurry up and get a Pro then! 
