I've read queries regarding the usefulness of the physical card &/or luggage labels...
On several occasions, LHR/BKK/HKG, I've been in a business class check-in queue. This was usually caused by passengers with lots of luggage (from what I could see).
The patroling QR staff have spotted the gold luggage tags & ushered me to the front. A little embarrassing, but gratefully accepted none the less.
So, for me at least, the luggage tags have been quite useful & I'll try & obtain them if possible. I just need QR's co-operation, obviously!