Ibaka is a beast, it takes a bit of luck for anyone to dunk on him. Who knows how bad KL knees really are, but clearly a guy we need to manage minutes and keep healthy for the playoffs like the Big 3.
Point is he is really not a high flyer, so similar to Duncan we can hope any knee issues are manageable and don't detract from a highly productive career. Duncan against Clippers age 37 was a sight to behold, he looked very limber, quick, and displayed 1000% higher B-Ball IQ than DeAndre Jordan while abusing him. KL is more like the swingman version of TD to me, not the high flying monster dunking low BB IQ type that fans love to see get 4 dunks for a grand total of 8 points in a game. To average fan, a dunk is worth 10 points and they can have that fools' gold!