I do believe 2-3 zone is never worth the risk. The only clear advantage is in rebounding, where the boost could be a consistent factor in the game, also (without having any sense) on the offensive boards. But for all the other aspects I'm more than skeptical.
It could potentially be a solution against really poor teams, with several players without even a basic shooting or a flow ability...otherwise I don't see any possible advantage compared to a m2m. But even in those cases I'd never chose a 2-3.
3-2 zone is a different story, I like that zone a lot also against inside offenses but it won't be that effective if not properly built.