Like many others have said, this is a wonderful flat in an amazing location. My wife and I stayed for 2 weeks and Chris was very communicative both before and after arrival.
1) The flat could not be better located as it is tucked back away from the shopping on Oxford street (a couple blocks makes a huge difference). For scale, it's an easy 15 min walk to The British, The National/Portrait Museums, Covent Garden Piazza, Ottolenghhi (Nopi), Dishoom, Franco Manco (on Tottenham) and maybe 20/25 min walk to Downing, Calvary, Churchill War Rooms, etc. Bonus: there is also a small supermarket around the corner - 5 min tops.
2) Though we averaged about 15-20 miles per day on foot (museums included), we also made excessive use of London's amazing metro system (the Tube) which Chris' flat is centrally located to (buy an Oyster card prior to your trip); there are several lines within walking distance. You can get anywhere from his place with usually a single transfer. The longest we had to wait for a train was 2 minutes and that was on a Sunday. All other times it's about a train per 30 to 60 seconds. We used Oxford Circus as our main Tube station (5 min walk from flat) and could not have been happier.
3) The flat itself is very comfortable for two people. The pictures are accurate, the two love seats were very comfortable, heating was great (beware too much heat in the bedroom as the amazing duvet is all you need), new hair dryer, etc. I don't think we were missing anything in the flat (other than what we needed from the market) in our two weeks. We made use of the washer every other morning- about 30 min cycle.
About the cable (TV) and internet. The cable was awesome and you can make use of the DVR for later use. As for the wireless. This, on the whole, is great. We picked up SIM cards from the wireless provider company 3 (three) at the airport. All you can eat data +phone and texts for a month at 20 Pound. Chris uses a hotspot from the same company. It works great in the apartment, but you will sometimes find an outage of several minutes. This, we found over our 2 weeks, was the wireless provider, not Chris' set-up. We would notice outages across the city for minutes at a time. It's the best thing going in London, so this is just a heads-up - it always resolves itself. When I 1st experienced this I emailed Chris and he was on top of it within minutes even while he was on holiday!
Chris' flat is my London home and when I return, I'm not even looking anywhere else; I'll work my trip around the flat's availability. 5 stars across the board.
Bonus: There is a Sam Smith local (the Champion) on the corner. No music and 2 pints for 6 pound something.