Regardless of BA champions or any other title bestowed on various personal, service levels onboard will not improve until the cabin crew sort out their differences with each other. This includes mixed fleet who seem to fly the 'better' routes, main crew who show their teeth every time there is a change, which ultimately results in some sort of salary loss. Until the crew work as one, then I don't see any improvement onboard.
It was the same when BOAC and BEA joined together back in the 70's. the crews didn't want it and service levels began to slide on both sides. Again back in the 90's BA introduced Mid fleet and that didn't work for long because of route structure and allowances.
When the crew are all on the same structured salary and allowances together, then I believe service standards onboard will start to rise again. BA can safely use the slogan 'To fly to serve'