"Play music by Milk Inc."
It might ask me if I want to buy milk. Or if I say
"Play Acappella by Kelis."
It will respond
"Sorry, I can't find a capella in your music."
Stuff like that. And it is borderline unusable at all if I'm out of breath, like when I'm running and handsfree controlls makes sense.
Siri doesn't need a speed improvment. It needs orders of magnitude better AI.