I would compare a transfer between LCY and LHR as a transfer from EWR to JFK. Expensive and time consuming my taxi. Extremely messy by public transport with various changes on the train - two changes as a minimum.
Taxis and public transport in London are extremely expensive by US standards !
There are no airport hotels attached to the MAD airport. There are free hotel shuttles or you can take a taxi - but then even a trip to the Hilton Madrid Airport will cost about $22 (one way), probably the same to many airport hotels.
You expect your bags to catch with you overnight? Good luck! Friend's experience for a missed BA connection at JFK-LHR-BCN took 3 days for the bags to catch up in BCN.
Last edited by KenJohn; Oct 28, 2011 at 5:40 pm