In some particularly nasty weather a couple of months ago, I was kept waiting at LHR for over 2h30 for a gate, on arrival from AMS on BD (and the only available gate was domestic, so there was another 15 minute wait for buses).

This was following a 1h delay in the terminal at AMS, and a 1h delay on the tarmac at AMS. Not a good journey. FWIW, the crew handled it superbly.