I don't think Rondo is a great passer. He's quite decent and gets more attention because he does do the flashy ones quite well, he also does alley-oops well.
But other than that, as far as timing, ball speed, accuracy, bounce pass, he's way behind from the greats.
He does have a knack to find the open man, but there's still a lot of room for improvement in the actual delivery of the pass.