To be honest, I do think that Rondo might be a little overvalued as a defender. He's arguably the greatest "stealer" in the NBA; however, his willingness to roam often lets his man get easy looks.
Now that's not to say he's a bad defender. However, if we are going to take shots at Kobe, Rondo probably deserves some criticism.
Reciprocally, I don't think KG gets enough attention. To me, KG is the defensive player of the year every year no matter what numbers Howard puts up. Howard has the gaudy stats, but KG gives the results.