If you have not used a spinner before then I would suggest that you first use something that require more human imput like The Best Spinner or Spinner Chief in order to understand the basic principles. However if you must go fully auto then I would suggest you go for Wicked Article Creator. I have it and understand it is similar to wordAI but a one off fee of $47.

There is a completely new feature - Team Version, SpinnerChief 5 is the only article spinner that has a team version now, which is especially designed for team using, create/manage/use team thesaurus with team members together, and multi-users can use the license on different computer with themselves member accounts. Manager can manage team members easily.
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.
I mean you can do that as well of course and it all depends on what SEO project you will be working on. If you just need an extremely high quality article for some Tier 1 project, you can head to the website and do some manual work, but if you need content for, say, your GSA SER campaigns, you just need to connect WordAI to your Kontent Machine and you are good to go. Now, let’s take a look at WordAI’s “Standard” spinner.
It looks like the creators of Spin Rewriter 9 .0 have really put a lot of work into creating a piece of software that creates readable content. However, Google isn’t stupid and there are a lot of things that can go wrong when you are trying to “manipulate” Google into giving you more traffic. Google hates spam, badly written content and duplicate content. These are all things that Spin Rewriter 9 .0 is capable of creating. You simply can’t trust a piece of software to write content for you in my opinion.