Overall, clean and very comfortable bed. Well designed rooms, good bathroom/shower. Good lighting options in room. Design allows little chance of leaving something behind as you rush to the next flight.
Heathrow, on the other hand, is terrible, uncommunicative, chaotic and less than friewndly, especially if you have to change terminals.
But if you must stopover at Heathrow, Yotel offers a very good onsite option for a rest, sleep and shower.