Zooker
You can just turn up and fly, but unfortunately I personally do not have access to our company Gulfstream, so like everyone else we have to use lounges, or a seat in the terminal. Lounges are as you say a better class of waiting room.
LAX-LHR
I think most people either head for home or hotel on arrival, though I do grant you some go straight to work as I have done in the past when outbound. I think it depends how far you have travelled, for example a Trans Atlantic Red eye - straight to the office, in bound from say China may go to hotel first drop things, then office. This is my experience of visitors who have come into our office recently.
Regards
Mr Mac