I have never used the BA lounge in A terminal but Air Berlin also has an "exclusive wait area" for status members in C terminal. It's over by Gate C38, you can use the Fastlane on that side of the airport and use the bridge inside the security area to get to any of the gates, though it's a bit of a walk up and over the baggage area. To get in, you need only your card or the ticket which will open the doors to the lounge. It's also upstairs so if you have heavy stuff and don't want to bring it up and down then don't bother going there. There is no elevator.

The "waiting area" has only a coffee machine and drink machine. There is also the normal newspapers and stuff and sort of cafe style tables. There are power plugs around the rooms as well.