To agree with the thoughts of other reviewers, I believe Six Penn to be a fantastic drink/graze space and less worth it for a full-on dinner. On a clear night, the rooftop deck makes for excellent drink-consuming and people-watching, and their cocktail list downstairs is usually spot-on. The bar menu and desserts aren't breaking any culinary records, but we've enjoyed seasonal chow like a pumpkin roll, pirogues, and seared scallops without complaint.
Without having sampled it, I can't speak to the quality of the dinner menu, but the price-dish matchup seems inflated to me. Entrees in the 20-30s for typical American fare.