I would admit that this is probably the only Japanese restaurant in Pittsburgh that offers a more traditional, non-Americanized Japanese cuisine. However, for their price (15-20$), the quality is sub-par at best.
I believe they are most known for their sushi, oft used in japanese society meetings - which i found them fine. Their fried items (tonkatsu, tempura) seemed too oily - likely a result of reusing the same oil, the rice too dry (kiss of death for me for any japanese eatery) and the miso shiru too salty. For a price around 20$... It is unacceptable.
In Japan, Chaya quality would be par with cafeteria food. Would you seem justified in paying 20$? Unless you are dying for sushi, I would recommend going to Kiku for a similar price range (may be slightly more expensive).