Yeah, I uninstalled everything before doing the update, just so I could start fresh with everything. But even still, some of those addons that I wasn't able to find updates for left stuff behind in the database and were throwing a lot of errors. I think I got that all taken care of, but it's hard to know for sure yet.
Php-fpm keeps randomly spiking to like 80%+ cpu usage though, so I'm trying to track that down. It's gotta be either an addon or XenForo itself, I would think. I really wish the CP had a resource monitor or something for all of the different components.