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.
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.