I arrived late and was unfortunately not able to get upgraded to one of their suites. They were all sold out and I was instead given a Fabolous Room which was very nice and typical W. Comfortable bed, flatscreen Tv, separate sitting area and an open bath room, but without a bathtub which more and more hotels decide to skip. The bathroom also had the great Bliss products which you can find in every single W room in the world.
Another signature of W is their Whatever, Whenever service and it worked very well during my short stay. The staff had a good attitude and I was in general happy with the service. It was up to the W standards as well as the facilities, but with rates starting at 600 dollars you would expect an even better experience, but that is just how London is. Like New York or Moscow where you know value is almost impossive to find.
My opinion: Great experience.