I had a thoroughly enjoyable 2-night stay recently, in Room 113. The room, as per many reviews I've read, was indeed very small - but I loved it! It was perfect for me, as a solo visitor. The air con was amazingly efficient and responsive, the bathroom small but perfectly formed, and the shower was lovely too. Had two really restful nights in the comfortable bed. I was fortunate in that my room overlooked the rear of the hotel, so I didn't hear traffic noise at all. All very clean and comfortable.
The only negative was, on arriving at breakfast on the first morning of a two-night stay, it transpires I hadn't been checked in the previous day (despite having done so with a member of staff). I had apparently been listed as a "no show" - not a problem as I was subsequently checked in, but from a H&S perspective I found this slightly concerning.
The hotel was a short walk to Earls Court underground and placed well for exploring. I also loved that I could walk, in 20 minutes or so, along very pleasant, tree-lined roads, to my favourite London park - Holland Park. Really recommend a visit if you stay at this hotel.