So loading the forums from an article is causing Safari to hang on my MBPro. It's fine on Chrome, but Safari is hanging. SafariWebContent spikes in activity monitor, and it looks like one of your advertisements is causing the issue. For an Apple based site I'm surprised no-one complained about this sooner.
Scroll down to the comments, and click on, "View All Comments."
Sometimes it completely hangs safari, scrolling stops, other open tabs can no longer scroll content that's outside of the current window. You have to quit and relaunch Safari. Once you do, you can get back to your previous tabs, etc. but it's super annoying.