If you want to see some of the best ACTING on Broadway right now, I'm told to go see NEXT FALL.
If you want to see great (and some legendary) performers sing some Sondheim, I'm told to go see SONDHEIM ON SONDHEIM.
Neither will disappoint, I'm told (I cannot say for sure because I haven't seen them). Just go with what you are in the mood for. If it were me, I would choose NEXT FALL.
"The Spectacle has, indeed, an emotional attraction of its own, but, of all the parts, it is the least artistic, and connected least with the art of poetry. For the power of Tragedy, we may be sure, is felt even apart from representation and actors. Besides, the production of spectacular effects depends more on the art of the stage machinist than on that of the poet."
--Aristotle