The food is excellent, service is great, and prices fantastic. You can take a lunch date here and leave with a $20-50 bill, or grab lunch to go for around $8-15 for yourself.
The atmosphere inside is nice, if not a little cramped. It can get a bit noisy in the main seating area, but the food presentation is great. I believe there is also outside seating which would solve the noise issues.
All in all, Nicky's Thai Kitchen is one of those great little gems in Pittsburgh. You won't be sorry you tried it.