My own experiance of BA crew in the air has been ok, although not excellent. In discussions found them to be "deppressed" about the state of their airline and concerned for the future. I have sympathy with this as the product has been poor, ie old planes , old IFE, and average food.
I have found some of the ground staff at Heathrow to be very poor. For example overheard a conversation in Business class lounge with a passenger asking for a glass of champagne at 11.00am and being told there was none available (seems strange to me). Upon the passenger questioning this very politly she was asked by ground staff "did she have a problem" ie drinking issues. Not quite what you expect in a customer facing business.
In general I would say that previouse posts saying that people have bad days etc is very true, and is true on all carriers, it just seems that when BA crew have a bad day everybody else has one as well.
In closing I have to say that I have voted with my feet and no longer fly with BA unless no option, but this has been down to abandonment of Northern England by their managment not the crews. On the plus side their crews in my experiance do know how to have a good party down route !.