The thing about Rondo, which I love, is that he ALWAYS steps up his game come the post season. That's all that really matters. Who cares what stats you put up in the regular season if you can average triple doubles during the playoffs?
There is not a single player in the draft guaranteed to step up when it matters, and the list of players who step up during the playoffs is minimal. Rondo could possibly be on the top of the list - That is why he is so valuable.