The property we stayed in was flat 4, with one apartment per floor. It was very spacious and comfortable, but old and tired, with only very basic amenities and cheap furnishings. It is probably only 3 star quality, but it was very clean and in an excellent position, within easy walking distance to two rail stations and many of Londons attractions.
Unfortunately being so central also meant it was quite noisy, so for light sleepers, this place may not suit.
We also found the showers being over the bath tub to be quite difficult and dangerous to use, as there were no rubber bath mats or grab rails and the bathtub was very slippery. It was quite expensive for what was provided, but then again, central London is not a cheap location.
We would recommend the flat, but with some reservations.