Wow. It's so weird seeing Civfanatics on XenForo. It just doesn't look right and it feels... off. I'm not sure how to take this change. I'll get used to it for sure, but it'll take a while.
One complaint I have is that the Report, Like, Reply, etc. buttons are just links at the bottom of posts instead of full-fledged buttons. Maybe that'll get fixed in the future, but for now they are too non-significant.
Also, the default light grey background makes all the text hard to see. It strains my eyes.
Other than that, with some ironing out, this could be good.