I can fully recommend Marco's place for a stay in London. The location is next to some major transportation options and we found it very easy to take a 10 minute bus or tube ride to the major tourist spots. If we were tired it was almost always less than 15 pounds for the five of us to take a cab back, which is about the same price of 5 tube rides with an Oyster card.
The building is on the older side with some old building idiosyncrasies but nothing that made a noticeable impact on our stay at all. In fact the apartment is very well decorated with some awesome views. Plenty of towels, pillows, and of course the basics were all there. Tv and wifi were active and problem free.
Marco communicated very well with us, met us at the door at check in. We visited his café and had a great breakfast there. There is also a pub extremely close nearby that has great beer and pretty good fish and chips, it has the word Prince in the name, can't miss it.