Spinrewriter has a decent Google pagerank and bad results in terms of Yandex topical citation index. We found that Spinrewriter.com is moderately ‘socialized’ in respect to Facebook shares (20.2K) and Google+ shares (41). According to MyWot, Siteadvisor and Google safe browsing analytics, Spinrewriter.com is quite a safe domain with mostly positive visitor reviews.
Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.