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.
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.