We've been working fine since the end of 2011, we are running a service website with lots of good quality data. We actually do service for people, but don't charge -- all our monetization is from Adsense. No Google update has ever scratched us. We were always rising steady, little by little, with no off-site SEO, no linkbuilding, no article-marketing, etc. Not much on-site SEO also -- just good accessible info. We bet on content being the king and on good customer service.
On August 7th we noticed unhealthy dives, and yesterday (15th) / today (16th) we were cooked: traffic dropped by three times, revenue drop to half yesterday and to 20% today, compared with before August 7th. In fact, we just had the worst days since February 2012!
If Matt Cutts, or whichever Olympian, is checking for "Google traffic drop" and finds this thread -- we never had a complaint, we have on our website everything there is to know about our niche, including links to government websites, where appropriate, we try to be as useful as a website can, yet we got crippled.