You don't actually have to go through security anymore to get to the BA lounge in Satellite 5, but (A) the lounge is truly disgusting. If the rest fo the terminal wasn't even worse, I'd just sit in the main terminal; and (B) they seem to be quite strict about who they let in - I overheard a Silver card holder the other day complaining very loudly (and rightly, in my opinion) that he'd been denied his right to use the lounge even though he was flying in coach.