4 hours (let alone 7) is too much imo. The CCR is nice, but is just a well decorated waiting room. 2.5 hours is fine - grab some breakfast, possibly a treatment (if they aren't all booked), have a drink and go to the plane relaxed.

When we flew Concorde we got there 4 hours before hand, and I was itching to get on the plane after 2 despite the high quality free flowing booze and appearance of the afternoon cake tray.