Hilton London Heathrow Airport (at terminal 4) {GBR}
Namely, that there is NO free transfers between the terminals and the hotel. Unless of course you are departing from Terminal 4, then you have transfers - your feet! It is about a good 6 minute of brisk walking to get to the hotel from the departure levels of the Terminal. When I checked in today to enquire about the transfers to Terminal 3 the next day, I was told that I have two options. One to take acab for a £12 charge (US$20) to get to another Terminal, or I could walk to T4, and take the Heathrow Express for free. But that is a nightmare in itself.
You have been warned! I guess I will cough up the cash and take a cab tomorrow. And will never ever stay at this property again. Only good thing is that they haev free interne access in the rooms!