Not sure, I really like both players though. Neither guy lived in the paint enough that I'd win a championship (I think as a big, to be the first option offensively on a championship team, you have to be very willing and able in the post, unless your squad is exceptionally stacked offensively and it's more of a scorer-by-committee deal). Both are top 10 (maybe top 5?) defenders ever, and would be in my top 15-20 players in an all-time draft.
In certain situations KG... in others Robinson. KG, Duncan and Bowen would have been the best defensive team ever. But Duncan and Robinson overlap some where as KG could have been molded to fit in with Duncan better. KG would fit in with more team concepts and different situations where as Robinson would be a big time fit in others.
Damn this is close. KG was just as good or a rebounder as David so I will call that a draw. Scoring I will take David. Passing I will take KG. Defensively, both are among the best to do it. David can defend the paint better while KG was more versatile, even playing many minutes early in his career at SF. I think skill for skill KG is likely the top 7 footer ever to play. But David is likely the most athletic and skilled CENTER ever along with Hakeem. So it might come down to David being a dominant center while KG was a dominant 7 foot PF who was actually a swiss army knife kind of player. I think it might actually come down to what u need. They are actually two different players when u think about it anyway. David while mad versatile and loved to faceup was still dominant as hell in the paint. KG is among the top 5-6 most versatile players ever and can plug more holes than David.