just looking at their ability on the basketball court and what they could do from play to play or game to game, I think Kobe takes it. So if you're picking teams for a pickup game, you'd go prime kobe over prime duncan. However, the NBA isn't played that way and Duncan wins in all the extra stuff we don't always think about. So 1 game of Kobe is > 1 game of Duncan but 18 years of Duncan is > than 18 years of kobe.
Kobe is still probably top 10-12 all time, he's right there with Oscar Robertson.