This year's playoffs showed the danger of building your team around score-first point guards. Westbrook and Rose had moments of brilliance, but they suffered terribly in efficiency against playoff defense and magnified the problem by ramping up their usage.
They got their teammates less involved and tried to take more of the scoring burden when things got tough. They were consistently frustrated by help defenders in the paint and baited into bad jump shots.
Rose (not so much Westbrook) still has the advantage over Rondo in things he can theoretically do to help his team win (score efficiently in volume, hit 3s, draw fouls and hit free throws), but Rondo still does the less glamorous things better (rebounding, good shot selection, controlling the pace, setting up scorers, applying defensive pressure).
Given how much positive affirmation Rose has received for being the top gunner, I would be surprised if he shifted gears and focused on improvement as a floor general and possession generator. Thus, I feel Rondo will be a more effective player for his team in the foreseeable future.