Aviance have handled the BA flights for a long time the girls in the BA uniforms were just for the ticket desk. LH,SK are just 2 other airlines that have staff in their own uniforms but have a handling agent doing the check-in and boarding etc.
IB,TK,US,CO and BD are some others.
I work for a company associated with Aviance so I can see what loads are like on the BA flights and t be honest they are no different to last year before EI restarted DUB-LGW.
Loads average about 50 with about 10 of them being business class passengers.
They still manage to achieve full loads on Friday/Sunday evening etc.