I'm impressed by the flexibility of my K10.
It sounds fantastic with every source I've tried so far, including direct play from a MacBook, iPhone etc.
My Shure SE846 were really picky (made me even order the Chord Hugo, and in fact the Hugo made it shine), however for the K10 the source is less critical, and I love that I don't need to bother about the source.
That said, I do prefer the sound of the K10 with a Hugo or AK240 highly over a direct play (MacBook, iPhone), but you hear the quality of the K10 also with cheaper sources (where the SE846 suffered).