Pretty standard. The line moves pretty fast, thanks in part to the clerks asking anyone standing in line with a package if they're just dropping it off. Nearly everyone with a box is doing exactly that so it gets them out of line because they can just drop it at the counter and peace out.
There's a small selection of greeting cards, bubble mailers, boxes, and more for you to peruse before hopping in line, and like any post office location you can buy stamps at the counter. The available designs are displayed at each register so you don't have to ask what they have available.
One woman did get a bit of lecture for showing up to her passport appointment late - they close the passport facilities earlier than the office itself, so make sure to give yourself time to arrive or you might be out of luck if they've already locked up that portion of the office for the day.