I am still seeing an upward traffic trend for now. A few more of my pages have a new cache (about 50% of my pages), and my traffic is up about 72%. Traffic is increasing in very close correlation with the the appearance of new cache and they are appearing very, very slowly. I am able to tell because it was a sitewide change I made about 2 weeks ago. As of now, about half of my pages are cached with that tweak.