I've only gone to the rooftop bar happy hour at Six Penn and if you can score one of the two tents up there with comfy couch seating, then you're golden. They have decent cocktails and a slew of unhealthy but yummy appetizers. The service was a bit uneven, but it was a gorgeous late afternoon well spent. Be aware that traffic and parking might be issues in downtown Pittsburgh, especially if there's a game going on. I parked at the $8 garage across the street and I'm glad I did because afterwards, I got to see the game end fireworks from the parking garage which turns out to be a perfect vantage point, especially from the roof of the garage.