The machine supports color on high resolution, has a very advanced sound chip (for that time) and is the very first Apple II that came with a GUI (GS/OS). This OS became System 6.0.1 for the Macintosh machines.
Fun detail is that this is the first time “Finder” is being named and used, still known today, in the latest OS X.
Despite the 16-bit CPU is this machine fully backwards compatible with the other Apple-II machines. This is basically the ultimate Apple II.