I think I am more frustrated with this line than any other on Flyertalk - it's been trotted out continually since the move to T5 with no evidence whatsoever.

While I completely buy that the automated T5 systems mean that priority bags will (should, could) be separated into priority bins, irrespective of the colour of the tag attached, I have seen precious little evidence if that actually happening, as translated into priority bags arriving at the destination belt in an early wave (I am the anti-CWS and check a bag most times I fly for more than a couple of days). This is flying in all classes and as a gold since before T5 opened.

Coming the other way into LHR I have reasonable confidence that some outstations do sort bags by priority and load the containers accordingly, given the tide of orange I sometimes see at the belt. I'm also reasonably sure that this is often done manually using the orange/yellow tags, as I've had a few occasions when the tag has fallen off one bag and that has come later.

I'm not saying that there's no airport that does effectively and automatically sort BA bags by priority - I just haven't seen any evidence of this actually happening, and certainly not outbound from Heathrow.

Note that the "when everybody has status, nobody has" argument doesn't apply because BA explicitly only offers priority baggage handling by class of travel.