defense. Good fundamentals, not extremely big or strong, but good mechanics. I'm the type who notices when bigs get used underneath, and I can't remember Noah being used very much. Noah definitely blocked a lot of shots, I'd say he was very good at anticipating when and where a shot was going to go up.
On the other hand, Noah was not laterally quick. If he had to defend the perimeter, quicker players could blow by him. That was his weakness.. a little undersized underneath and a bit slow outside.