Chaya is very good. Not the best I've ever been to, but very good, especially for Pittsburgh. The ingredients are extremely fresh, and the place is run by a Japanese family; something that's become rare in many places these days. Please go here over Nakama, and don't use Nakama as your "baseline" sushi experience.
It's affordable, and very authentic, and acceptable portion size. Granted, I haven't been to Japan yet(on my to do list) but I consider myself well-versed on sushi. FYI, if you take your wasabi and put it directly in your shoyu, please stop. Or at least don't write a sushi review!
They also let you bring in outside wine, but they do charge a small corkage fee.