Wise words from Gonzo, as always. Understandablt as he is a current Heathrow ATCO. It's only in recent times - and long since I retired - that I've heard about these categories! I managed a liftetime in ATC in such ignorance so I am drawn to the conclusion that they matter little to ATC whereas the aircraft type is of great importance.
Herc708..... you don't by chance drive the type of aircraft suggested by your handle?