It must do some amazing things

Well, it doesn't do much more than what you can already do with a PC. However, it does them all automatically, with a very simple idiot-proof user interface, and it does them in a package that fits in your home stereo system.

For instance, the act of adding a new CD to my MP3 collection involves a total of two button presses on the HSX-109. One to open the CD drawer, and one to confirm that I want to record that CD instead of just playing it.

It has some other advantages over a PC, for instance, optical outputs, nearly-silent operation, stable "no-crash" functionality, and no tricky software to install and configure.