After taking a taxi from St.. Ermins to LHR , I arrived about 2 hours before the flight. Got my boarding pass through a machine and went to an Elite line to get passport screened. Then saw the elevator for the Virgin Atlantic Clubhouse. This was what DeltaOne members have accessible for a lounge in LHR.
The clubhouse is probably the nicest business class lounge I have been to except for the Turkish Airlines lounge in IST. Its large, lots of different seating areas and things to do. There are nice showers, a kids room, buffet style food, a dining area with made to order food as well. There is also an extensive drink menu. They also have paid services such as a massage, shave, nails, and hair cuts.
I had some eggs benedict, which were delicious and several different tastings of different champagnes drinks as well as specialty gin drinks.
While the lounge had a lot of people in it, it never really felt crowded as there was always room.