Of course there are the numerous error messages and failures to load.
And there's a twist on the old latency problem - the computer ate my edits. I edited a post to add a little substance, saved it, and saw the new text on the screen. But when I came back later, the edits were gone and the post had reverted to the original.
Finally, something completely new and different - every thread opens fully expanded. No more compression of previously-viewed posts. Now **that's** a real incentive to participate in one of those monster threads that's been going on for a few months.
Please, please, please fix the site.