In my experience, contesting the shooter works in every situation except for in the post. Almost every shot out of a post move seems to go in. Aside from that, I actually agree that there are a lot of positives. First off, the AI switching is faster and sharper, and that's a huge step forward in bball defense. Now you're not stuck with mismatches for a whole possession if you trap or double team to get your way out of those situations. The off the ball defense is great, the block/charge collisions are great, and a little overlooked right now. People are only pressing the take charge button to actually take charges, but it is also extremely useful just for putting penetrators on the line.
If people used the B button more, the defense would double in "sim" quality.
Also, the increased options out of the double team are a step forward for basketball defense. We have step throughs and more variables overall so double teams feel much less scripted. Lastly, the increased ball physics make the passing lane defense much, much more logical and does the same for the shot blocking and alley oop defense.
The shooting slider needs to go down in 2k9, but I think that skews the perception of much improved defensive mechanics.
Hehe, on topic, nice job on the review. I don't have the game, so I can only compare the accuracy of the review to the demo, but the content, perspective and insight were all head and shoulders above the generic site sports review.