Ebert didn't much like The Sisters. I see his point. Even watching the film unfold in the setting of the contemporary faculty club, you feel chill wind of the steppes. These are Russians, transplanted to New York.
But never mind that: this is a wonderful workshop piece, a chance for a bunch of superb actors to their stuff. Lots of range, lots of depth, and tons of acting against the grain. It's like coming early to a ballgame to watch batting practice. Some wonderful readings, and fine writing.