SpinnerChief is designed to generate unique articles to provide content for websites and increase site traffic. It does this by spinning one article into multiple versions of itself, replacing certain words, phrases, and sentences with alternate versions of themselves. SpinnerChief can identify parts of speech, correct grammar errors, and use intelligent auto-replace methods until the article is both human-readable and passes Copyscape (a plagiarism checker). The SpinnerChief API allows developers to access SpinnerChief's functions from within other programs and can spin articles in 27 different languages. 

Looking at both spinner’s spun articles, they both seem to generate spun content that looks pretty good. Both have some grammar issues I would correct if I was posting it on a high tier 1 site, but overall SpinnerChief produced better content. Not sure if WordAi is being overly aggressive on the spins at the cost of quality. This test is very hard to call. If you go by raw numbers, SpinnerChief won. I want to leave this up to you to decide which one won. Winner none – draw!
For a blogger who has to publish multiple blogs on daily basis, it is tough for them to write unique content, especially when writing on same topics. In that case, spin bot tool could be used to avoid self-plagiarism and to maintain the quality on blog posts. As spinbot change synonym automatically but you can pick the most relevant synonym using out tool.