I've noticed that threads I haven't viewed before don't finish loading most of the time when I click "first unread post" instead of the thread title (this has always been a problem, however). Posts that contain GIFs also load really slowly, but I suspect that's just a problem with my internet connection.

Now that I think about it, things do seem to be loading slowly than normal. I think I just assumed it was a problem on my end, since I frequently have sixty or more tabs open at once (not all loaded) and the browser slows down after too many tabs are loaded. They were just as slow to load when I first opened my browser, though.