This does sound insane, and a bit different from my last experience, albeit 2007:
Get off plan, walk for a long way following signs towards arrivals exit, spot sign for UK residents/nationals, no queue, a sleepy fellow looks at my passport and face, then I walk through to the arrivals area and try to find the underground station.
It's those from outside the EU/EEA who have to do that. For those within, it's much the same, but also with e-Passport gates (that take a photo, compare with passport, etc.).
Get off plan, walk for a long way following signs towards arrivals exit, spot sign for UK residents/nationals, no queue, a sleepy fellow looks at my passport and face, then I walk through to the arrivals area and try to find the underground station.
Have things changed that much?