In the last few weeks, the 'review' button at the top of stackoverflow.com has become very slow. I can count to 20 in some cases (but not always).
In a perhaps related phenomenon, I believe that test questions in the queue often trigger a level of extreme slowness all their very own. If I click on a queue, or 'next' after a review, and the periods sit there throbbing for a good long time, chances are that what will show up will be a review audit.