It can be fun but it's one of those "Hotspots" - well, technically, it's no longer "hot" (this being Manhattan and people moving on to the next place after 5 minutes).
You should expect that type of crowd though- kids with money, or kids pretending they have money. I'd say dress to somewhat impress.
It's sort of what Spybar was in '97.
http://preppylife.tumblr.com/