I guess I always got lucky at this hotel as I read so many horror stories.
I've always been upgraded to a high floor suite overlooking Green Park (5+ stays) - spacious room and huge bathroom - and while not modern looking in the room like a Westin I kind of liked the English charm of the room. My only things I wish were better (its been 2 years since I've been to London) is the heat/air seemed difficult to control and the TV was rather small with limited channels.
I really liked the proximity to Green Park to go jogging - close walk to Picadilly or Hyde Park/Knightsbridge.