Pegasus seems to be THE popular gay men's dance club in Pittsburgh from the few books I had read. On a Saturday night, it was starting to fill up a decent sized space by 11:30-midnight, although it was still somewhat sparse by the time I left. While the ambience was not NYC house/hip-hop, the DJ seemed to have some knowledge of these genres as I gathered from my hour or so there. The dance floor was decent, consisting of several polished wooden levels; many people seemed to prefer watching the dance loor than actually going on it. The bar as a whole had a lighter (less dark), spacier, cleaner feel than many other gay bars I'd been to.
Although some of the clientele had sure-fire signs of trendiness, on the whole, the crowd seemed pretty unpretentious.