The hotel is situated on the covered overhead walkway which links the station and the three terminals and is within 5-10 minutes walk of all departure / arrivals. It also has great free wifi. Those are the reasons I always stay here when at the airport, however in other areas the hotel isn't quite so great:
It can be expensive unless booked well in advance (I've paid between £65-145 per night for similar rooms).
The food and drink is very expensive but there is very little else before security so they have a monopoly. I've not sampled the food but it looks ok.
The rooms are clean but slightly old fashioned, some rooms only recently getting LCD TVs. The bathrooms are nothing to write home about and some standard class rooms only have showers (not baths).
In summary everything is adequate and I wouldn't recommend having the hassle of staying further away, just don't expect all the high standards found elsewhere in the chain.
On this stay in particular I found service good, after booking two nights separately they combined the bookings and upgraded me for free (I had paid through the nose for booking one of them last minute)More