Booked twin room and it was spacious for London. There is meant to be complimentary still & sparkling water, although only still bottle was there.
Had to fight hard to get breakfast included, even although my booking stated "complimentary breakfast buffet" on hotel description. Eventually this was granted but I really did have to stand my ground to achieve it. Waitress at breakfast was wonderful, very cheerful and polite - just what you want to start your day. A good selection for breakfast.
The aircon had a dripping/clicking noise which drove me mad and I eventually had to switch off during the night.
There is only 1 pillow each. You can phone for extras, but why not put them in the wardrobe like most other hotels?
The Emirates chairlift is just across the road and takes you right to the O2 - a nice experience in itself.
Concierge were very helpful in organising taxis and luggage.
If they sorted the small points out then I'd have marked them 4/5 (very good), but at £190 a night then I expect a higher level of detail in which case, they only deserve "Average" rating.