Just to add to the previous. Totally Agree. The aviation company I work for based in the US and its sales people have long held the view that LHR is to be avoided at all costs. Not just T4 or BA - the entire airport. The BAA own it and run it so the blame lies with the BAA. The general view being " They could`nt organise a p**s up in a brewery " I have never been able to defend it or excuse it. Its a 3rd World airport. God Bless all the US carriers straining to launch out of LHR after 30th Mar with Open Skies......mind you the alternative or existing airport being LGW is not much better than LHR. Toss a Coin ! Guess what ? BAA runs both.
