It certainly looks like it. There does seem to be some major differences. Groupy is available now and is being designed to work across all (most?) apps you use, including file explorer. Sets is available to Windows Insiders and will roll out slowly. MS Sets is targeting UWP apps like Mail and Calendar, then office apps, then other Win32 apps that don't affect the task bar. (TechCrunch Article). To get the full power of Sets it appears you will need a Microsoft account and subscribe to Office 365. I like how Groupy is attempting to work across all apps right out the gate.
One feature of Sets I would like Groupy to mimic is the new tab button. Click it and it will present programs, called Frequent Destinations in Sets, to choose from. Working across PC's you may sign in to is also a huge plus.