I went from an iPod Touch to an iPhone, to a Sony S Series (which are heavily, heavily slept on), and now i'm back on my phone (Lumia). But i'm using three media players, & three fukking libraries, which blows.
I'm about two months from just putting everything on one damn home server, get an iPhone, & sync/stream the whole joint together at home. Ripping all of my damn vinyl is a chore and a half.
For me iTunes' smart playlists are a must have.