The hotel is a bit more expensive than it should be, and there are some aspects that are below 4 star quality, but I enjoyed my stay and would definitely return again.
Excellent location, easily accessible from High Street Kensington station and with lots of restaurants nearby.
Room: Absolutely tiny room. I didn't go for a suite or anything, but I really wasn't expecting how small the room was. And the furnishings were not even as good as budget 3 star hotel chains. A refurbishment and pricing the rooms according to their size would be an improvement - if I pay for a room that small, I want a much cheaper price.
Gym/spa: The gym was really big for a hotel gym. A couple of equipment were not working, but in general it was in good condition. I was impressed. The spa was nicer than some reviews suggest. The pool was a decent length, the steam room, sauna and hot tub were great additions - really small, but I mean they were there, and many 4 star hotels don't have them, so they were a big bonus for me. Also, the gym and spa were included in the cost of guests' hotel stay - no extra price.
Breakfast: The gluten free options were poor for a 4 star hotel, but staff were helpful and you *will* be able to eat an acceptable breakfast, just probably not as good as you might expect.