It is so very convenient for getting a good sleep before a flight especially from terminal 5. Bus 423 and one other (350? maybe) costs £1.75 and drops you off in front - takes about 7 minutes. It is a large place with no elevator but is only 2 storeys high so that’s not a big problem for many.
Very clean, coffee tea in room, quiet, iron and hair dryer. I’ll keep coming back.