It depends on the connection and the airline

I returned form Malaga to the US (AGP-LHR-BOS) Oct'07 and it was awful. There is an internal security check that took about an hour. This was, of course , after passing through Malaga security ( BA-AA connection)

I once arrived at the Virgin desk (LHR-BOS), and it was mobbed, with not nearly enough attendants to check bags. Check-in was by "emergency" only ( "will all those on the next flight for Paris in 2 minutes please come forward, and kiss the city of lights good bye")

The airport layout does not help. You wait in the central terminal, they don't tell you the gate until 30 min before departure, and some gates are 25 minute walk away.


OTOH, last time through was a breeze