Although the dedicated LHR F pax CCR is "exclusive", the food, IME, is not up to scratch for F! The eggs I had in the CCR last year were a total disgrace. The eggs I had in the EY lounge at LHR were perfect! Service too was light years better in the EY lounge. I am sure others experiences will vary
I find the service in the CCR a little lacking, but the food has been excellent.
Conversely, I've had a poor experience in the EY lounge at LHR. The buffet looked like a pack of wolves had been at it, and the table service meal was adequate at best.
Having said that, I'm told this is really unusual. I'm not flying EY again until June, so I guess I'll have to wait and see.