The Terrace Room is located inside the Omni William Penn Hotel (http://www.yelp.com/biz/omni-william-penn-hotel-pittsburgh-2#hrid:Gvi-plqilIq6o9BjosYv2Q/src:self), and just like the hotel, it is lavishly decorated with waitstaff that is on point. The tables from the restaurant that spill out into the hotel lobby are ideal for people watching.
The complimentary breakfast buffet has an AMAZING spread that most complimentary hotel breakfasts would never offer including Do-It-Yourself smoked salmon & smoked ham bagel sandwiches with gourmet cream cheeses, build your own omelette station, breakfast pastries that are so flaky you can hear the crisp when you bite into them, and various fruit and nut butters for all kinds of breads and toasts-- just to name some of the selection! If that doesn't satisfy you, can order from a menu which is also included in your breakfast voucher.
We also had High-Tea on a Saturday afternoon that was very pleasant. For $17 per person you get a tiered stand with assorted sandwiches, scones, petit-fours, with fruit jams, clotted cream, and a personal pot of tea. Delightful!
If you're staying at the Omni William Penn, don't disregard the "hotel restaurant!"