This is my favorite lunch spot in Regent Square. The lady who runs it is super-sweet and fun, and the food is of high quality (though to be honest, I haven't met a Thai restaurant in Pittsburgh that I didn't enjoy - except perhaps that place next to the Tobacco Outlet on Liberty Avenue in Bloomfield whose name I can't remember).
When I was in there yesterday, I was pleasantly surprised by how quickly our meals came out and how attentive the service was in general.
The calamari appetizer was especially tender and delightful (I'm used to calamari being a bit chewy and I generally like that - but this stuff was really just good and tender, reminded me of scallops.)
The decor is mellow and tasteful, in the summertime the restaurant feels like a nice shadowy-shady respite from the sun.