Originally Posted by
headinclouds
I'm not sure which is more confusing, the connection in T5 at LHR or the T4S-T4 shuffle at MAD.
With MAD you’d clear the Schengen border there, rather than at your final destination, which may save time on arrival.
The walking involved is generally longer than at LHR T5, but this is offset by (in my view) a more relaxed transfer security experience in MAD T4.