I really hate the phrase "clear upgrade". I hate the implication that players are interchangeable parts, like you could pick 'em up at an auto parts store, but for basketball. EVEN IF Chris Paul is a better player than Rondo - which I doubt, since I think Rondo is the best facilitator in the league - that doesn't mean he's a desirable 'upgrade' for us.
I agre with 'frombleacher' that the now infamous Celtic dry spells have a lot to do with them being a jump-shooting team. I think it has a lot to do, also, with them being an OLD team. They like to slow the ball down as much as they can, but this habit, which may save energy, also takes them out of offensive rhythm, and we all know how important rhythm is to jump shooting.
The magic Shaq and Rondo made together was something special. Dwight Howard has got to be thinking about it....