We flew home from Vancouver last May in F, we ended up at the airport early, but the check in & bag drop didn't open until 3 hours before our flight. I don't think there were any showers in the BA lounge airside, as others have said it's a very small lounge with snack type food and drinks. We got into it soon after opening and it was very quiet but towards flight time both the business lounge and the first lounge were very busy.