This ain't by far the best bus station: Its plain, kinda uncomfortable and not very clean. But I've seen worse, even from the same greyhound friends (e.g. Philly station, that one really sucks).
If the Amtrak or the megabus had more schedules I would never think about taking one of these busses. But man they have schedules. Pitt to phila about every two hours. You can't beat that.
That being said, don't expect a great service or big comfort. You won't find it here. WYSIWYG. No expectations = no disappointment.