For starters the software doesn't crush your machine as iTunes does to Windows.

Second of all, the physical player doesn't magically get a 'corrupted OS' or 'unhappy folder face' problem once a year - requiring trips to the Genius Bar.

The software does everything iTunes does like recommendations, folder tracking, etc - except you could get 'all you can eat' music for $10 / month.

In general the Zune HD device is just sick. Metro UI, intuitive touchscreen, and most importantly, completely unbreakable.