Cross Platform – Being a Mac user I prefer when I can fire up a program locally. WordAi is web based and therefore works on Windows & Macs without issue (Linux as well). SpinnerChief III Ultimate has a Web Api that allows spinning from the web, but we did not have much luck with it, so at this time we consider SpinnerChief a Windows only application and therefore requires me to run it in a virtual Windows Machine using VMWare Fusion. This one is a hard one to call because clearly WordAi wins cross platform, but it doesn’t have all the extras that SpinnerChief offers.
Google is getting VERY good at catching spun content so you'd better be talented at manual spins. If they DO catch you, of course they'll spank you... and hard. So anything you use spun content on is inherently AT RISK. Worse yet... Google gets better at finding spun/poor content every year. So in the longrun you're screwed. I'd weight your other options and see if you couldn't find a cheaper source for manually hand written content.
Content reword programming which is regularly called turning programming isn't your best arrangement. An article rewriting tool can help you a lot. A considerable lot of these product projects will turn out total trash in the event that they are used erroneously and regardless of the possibility that used right they won't change the structure and organization of your work enough to trick the greater part of the web indexes. On the off chance that the work should be possible by programming it can likewise be spotted by programming. Genuine paper rewording will bring about another report that will appear to be totally unique to the first with various passages and sentences instead of only a couple of words having been changed all over. Tools such as Spinner Chief can help you.
From personal experience Spin Rewriter is the best! like I still use it today. Its so easy to use (Just copy paste and the program do everything) Because of this tool I managed to schedule content and articles for 3 years, do you know how much time and money I’ve saved?!?! A LOT!!! Also i high recommend you pick their mothly plan if you are still in doubt
Article Rewriter is the best and free SEO tool that allows you to rewrite the article with flexibility. The competent tool, which allows you to post articles or blogs periodically, makes posts attractive and publishes the same in simple words. Rewrite the full content in few seconds. With the help of this tool, you can get rid of plagiarism. It also helps to improves your SEO performance faster than the before..
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.

Readable And Unique Content – the recommended settings for this one are the same as for the one above with the only difference being the change of the 1st input to “Readable”. This will create more unique versions of your content while still keeping a high level of readability. Generally, this is the best setting as it gets a good balance between human readability and uniqueness of the content generated.