A look at the rules always helps and I think it is what the previous guy was referring to:
2-3 Zone: Increased inside defense and rebounding at the expense of a lot of perimeter defense. Somewhat slow pace.
3-2 Zone: Increased perimeter defense at the expense of interior defense. Slow pace.
I believe that the rules were changed at some point, though. I don't remember the reference to pace for defences, although maybe I'm just not remembering right.
Run of the Mill Canadian Manager