Amtrak *used* to run out of the central facility in Downtown, near Duquesne Univ(I know only because I went to Duquesne, and it seemed smartest to take the damned train than beg for freakin rides to the Airport, in fact I *walked* to the bloody train station from The Bluff)...and really, the Amtrak trains are *clean*...and comfy..and roomy..and...well, really all kinds of convenient. And I was able to plug my laptop into the power outlet next to my seat.

The bus terminal in Pgh is not far from that..convenient also..but I would recommend the train more..as long as you can get a ride to Downtown, then you are good to go..