I fly IAD-LHR reasonably frequently, always in CW, and this absolutely chimes with my experiences. Many of the staff in the IAD lounge are superb, and overall in terms of the dining and drinking experience it's a very nice place to wait for an overnight flight. But the showers have really got grim in the past few months - poor water pressure and just a sense of being grubby and uncared for. It seems that they are no longer looked after proactively; staff always seem slightly surprised by the request to use them, which strikes me as odd in a lounge which serves almost exclusively red eye services.