Here's my unbiased take on this from a Lakers fan. Even though Pau has been playing better lately, and even though he has surprisingly kept his stats close to what they have been when he was in his prime, he's just not as good as he was for us in 08-09 and in 09/10. Maybe some of this has to do with Kobe shot-jacking this season and Bynum getting a much bigger role, but it is what it is. With that said, I still think he's capable of playing great and playing at that high level consistently.
Conversely, even though I love Rondo's game and loved what he did against Cleveland especially, I think that the fit wouldn't be the most ideal on my team because of the lack of consistent outside shooting. Teams exceed tremendously defensively against the Lakers, by collapsing on Gasol, Bynum and Kobe (major plus for the other team is also that Kobe will sometimes still try to score over two players, and that's where he gets a lot of his bad shooting nights) and daring either their Point Guard, Shooting Guard or Bench to make a shot - So far, it's been really effective and it is, IMO, why the Lakers were beat so easily by the Mavericks last year. Just my take.