When the C8 came out, I was tickled to death that there was a new device with new technology that would likely support matter in the future. I bought one. Then the first thing I tried was to join an Enbrighten switch with it and it wouldn't work. I pursued that for days, even sending it in for evaluation. I got it back, with the explanation that it had to be interference. I live in a rural area where I can't even see other wifi networks around me, so I doubt that was the problem. I even unplugged the C7 I had when testing with the C8.
So, in my case, I had a number of expensive devices that worked fine with the C7 that the C8 wouldn't talk to. But I continued anyway, maybe I could figure it out. When I tried to join one of my Iris V1 devices using the button that was clearly on the 'Add a device' menu, it didn't work, regardless of many tries. That was a real disappointment. I continued trying to get it integrated into my house for a while updating the hub and hoping for a fix, but instead, the button for Iris V1 disappeared. After finding the answer from another disappointed user on the forum, I just gave up.
Home assistant came to my rescue, and operates totally locally on a cheap Intel NUC that has way more power and capabilities for much less money. The C8 is gathering dust in the corner and will likely be on ebay soon for a good price. The C7 is a Zigbee gateway, soon to be replaced as I phase out the Iris devices one at a time at my convenience.
Hubitat may have existed before Lowes dropped the Iris and a substantial number of customers along with it, but what attracted a lot of people to the device was a route for those impacted by Lowes to continue to use their investment. I think that boost is inarguable, and definitely attracted a lot of new customers that were reeling from having their money wasted by a corporate decision.
So, call me a liar if you wish, but others have been attracted to Hubitat for exactly the same reason, and they were, and still are disappointed that the announcement and early advertising didn't say anything about the C8 not supporting the Iris devices. There was even a button for it that didn't work.
I found another solution that opens more doors than the Hubitat closed, and was cheaper as well. I consider my experience, and expense with the C8 as an eye-opening educational experience.
I don't think I'll be considering the newest 'Pro' version.