<I didn't know what I was talking about when I originally wrote this . . . see correction below.>

To address the OP's point, it's also worth noting that the Concourse C ORD RCC is not only worse than the others in that airport, it's one of the worst in the system (BWI is also less than stellar), and it's definitely the most crowded of the ones I've seen. On the other hand, to give a few examples, the lounges at IAD are decent--the D-cioncourse one is even usually fairly quiet--and the SFO lounge is lovely.

But comparing RCC to the lounges of major international players like Cathay Pacific, BA, Virgin, Singapore, Emirates . . . now that's a lost cause.