Has anyone had any success complaining to Google about a site that is ranking high, but is breaking all the rules in doing so?
You can submit spam report to Google. They wont manually downgrade the sites but they will include it in their algo
Look for JC Penny news, a big site who ranks well on highly competitive sites and discovered cheating..
not sure any individual that say something that they succeeded on that thing.. but if you really think that a website is doing something against google guidelines you can report them: https://www.google.com/webmasters/tools/spamreport?hl=en&pli=1
I reported a few competitors about 6 years ago. Some where hiding text and links, some where cloaking. It never made a bit of difference. The general rule is "don't waste your time trying to bring down your competitors. Build a great website and trust that in time, justice will be served."