I have not been, but I'll give it a go on my lunch break on Monday (have other obligations tomorrow).
I haven't tried nam tok. But it looks very similar to a dish they call sap-sap steak. And it's great. They also have beef laap, which is a bit different (finely ground beef), but it is fantastic. Even their pad thai is excellent. The papaya salad is also awesome.
If you're in the mood for soup, try khao piek sen. It's a favorite of mine.
Also, when they say spicy, they mean it. I usually do 5/10. One time I made the mistake of insisting on 10, and my papaya salad was more of Thai pepper salad.
P.S. I actually prefer to go to restaurants on my own. I'll go to Pizza Rev with a co-worker every Friday because he seems to enjoy it, and I'm nice. Saw fish there a couple of weeks ago with his adorable baby.
PSS Thailao put cucumbers in their water, which is super.