Flew QF10 LHR MEL dept 16.9. The showers in the BA lounge were unserviceable and we were directed to the AA lounge to use theirs. I was far more impressed by the AA showers than those in the BA lounge. That leads me to a question: Which lounge is the best at LHR T3 (with OW Emerald status) out of the BA, AA and CX offerings?