I've enjoyed my stays, and the rooms are definitely larger and more modern than those at the Hilton Heathrow T4, but the hassle of the busses (plus the fact that they aren't free) puts me off. When the hotel first opened, they had their own shuttle busses, but they stopped that (they said Heathrow forced them to stop), and after a few times using the Hoppa, I went back to the T4 and have used them ever since. Free train to T4, then a walk in the tube, beats the Hoppa busses for me, every time.