Prime Rib is truly celebratory, I agree.
It also speaks Washington, DC, which is not true for most of the restaurants in this city. There is a sense of place here. You really are in DC with all of the movers and shakers (mostly over 65 though and members of Woodmont Country Club)
With the exception of the office ceiling tiles, the restaurant is beautiful. It is like a swanky club with cool black and gold wall panels, and piano bar. But it all stops there.
The food is country club food at K Street prices. The food is an embarrassment in this day and age. But you should go there just for the experience (especially if you don't mind dropping $100 per person). I didn't find the wine values that Joe H. was talking about, by the way.