For my site, CPM and EPC are totally consistent with the last 12 months. However, since the Alegra update, I have lost almost all my natural traffic, and am receiving only ppc traffic, resulting in a 50% reduction in impression, clicks and, alas, earnings. I have been #1 - #3 for 100's of my top kw's, and now I rank maybe in the #600 - #700 range.
For an interesting perspective, my company name, which didn't exist before I created it, does not even come up in the SERPs point to www.mycompany.com any more. Sigh. This smells like a penalty to me, not just an algo change.