It's great to see the site move to a more modern technological foundation, especially with the expected traffic from the upcoming Civ6 release. That shows a lot of foresight.
However, I think that this migration could have communicated better in advance. Did I miss an announcement? Suddenly seeing the forum down for a couple of days without explanation wasn't very reassuring.
More importantly though, I have to say that the look and feel of the new forum is terrible right now. In my opinion, vbulletin was hard to beat in that regard. I hope a different forum theme can address most of these problems, and I also hope this is prioritised over other issues. To be a little more concrete:
* in general everything is light grey and there is little separation between elements on a given page, e.g. in threads posts are barely separated from each other, signatures are barely separated from posts, thread tools/links appear right as part of the post. It makes the whole board look very messy and hard to look at.
* many elements are plain ugly: smilies, color coding in the thread list, stuff like those speech bubbles next to threads or OP avatars next to threads, not to mention the pointless box around the avatar next to posts. All of these are minor and inconsequential on their own and might not seem worth disagreeing about, but they are all pointless and distracting and make the forum harder to navigate.
* why is it that an apparently more modern forum uses plain HTML elements for everything? Apparently every control element is a link or a checkbox now, even vbulletin was better than that.
* gloss, gradients and drop shadows are not more modern, only distracting.
I don't want to sound to critical because most of these seem like issues that could be addressed with better themes. Right now, most of the changes introduced on the user interface end make the forum hard to navigate and interact with, and definitely not a place to spend my time on if I don't have to. Another problem is that old CFC had a very distinctive feel to it, while this currently looks like something I could launch on forumotion in thirty minutes (not to disparage the work you did on the backend, just saying that the current appearance does not communicate that this is a grown and important community).
Additionally, I don't like the way this was used to dis- and enable controversial features through the back door. Likes may be just a configuration box to check on zenforo but that doesn't mean they needed to be added. More importantly, I disagree with the decision to just drop tapatalk support. Zenforo may be web optimised and not look like a mess in mobile browsers anymore, but that doesn't mean that interacting with it through browser is comparable to tapatalk. If you have to tap hyperlinks on a mobile browser page to navigate pages or quote people etc. it's not exactly comfortable to use. There is a reason tapatalk is the de facto standard for forums on mobile.