Traffic to my site (www.green-energy-efficient-homes.com) fell dramatically on February 24 - about 17% overall if I compare Feb 17-23 to Feb 24-March 3. Looking at Analytics I see that the decrease is only from US visitors, which means the algorithm change has definitely affected me.
I put a lot of effort into doing careful research on my site, and have had many visitors e-mail me with positive feedback. Most of the pages that are now ranking above me for common search terms are just online stores selling the products for which I provide more balanced reviews or analysis (electric heaters, LED lights, etc.). Those sites don't provide more valuable information, just more products to buy.