I can't think of a single bad thing to say about Roundabout.
To start, they brew phenomenal beer, and do a great job of providing a variety of styles. Having moved from the West Coast, it's great to see that influence in their beers, from the extensive use of California Common yeast to the first excellent IPA I've tried from Western PA. The Black Possum and Saison were big hits as well.
They only offer growler sales for now, but prices are very reasonable ($13 for most), as well as half growlers, and you can bring your own. Every time I've visited I've had a beer in mind, but have ended up trying the entire lineup. Steve was also incredibly friendly and had tons of brewing knowledge to share...it's a shame they can't sell pints, or I'd spend a lot more time there.