Avaince handles BA in Dublin - if you have status they will normally have perassigned your seat for you.
The desks are in the midle of the checkin area - the signs on the entrance doors are from the days when EI handles other oneworld airlines - they changed their business model in autumn 2004 and only service their own fligts now. This also means that non-status BA J passengers now have to use the Anna Livia Lounge.
Normally there are three desks open - with just hand luggage you can check in at the ticket counter.
If you are usingBA to fly to NOC or LDY you should use the domestic security line by checkin area 13 - yes I know LDY is in the UK - otherwise use the left hand security area.The other is full of Ryanair passengers