Similar experience to that of PresRDC. I stayed at the Belgravia in November for the first time and was upgraded (PLT) to a "studio suite" on an upper floor which, I believe covered the span of end of the floor. From previous threads, many PLTs seem pretty keen on this property and it does have much more of a boutique feel as mentioned above with staff who is very flexible. It became my London spg property of choice.