I order takeout from Pastitsio regularly and my family loves it. I recommend the pastitsio, falafel salad, beet salad, and grape leaves. I also recommend their baklava, which I consider some of the best in Pittsburgh, but the reason I like it is that it's not as sweet as others make it -- so your mileage may vary. Their moussaka is also good, but we rarely choose that over the pastitsio.
The staff is really nice and laid-back. The portions are not giant Pittsburgh portions, but they're appropriate and I think the price is totally right for the quality and freshness of the food.