Martin's place is very spacious and comfortable. The location is good - it is about a 10-13 min walk from either Charlton or Westcombe Park staying, both of which have good connectivity to central London (about 20 mins by train to London Bridge station). There are lots of grocery stores nearby.
We stayed there for two weeks, and had a very nice stay. The room has two desks and chairs, which is great to work from home from. We had full access to the kitchen and living room. The kitchen is well stocked with utensils for cooking. The room is in a shared apartment with two others who were friendly and helpful. The cleanliness of the shared spaces could have been better.
There was had a really cute kitten in the apartment - great place if you like cats!
Martin was really prompt in communication, and would recommend this place, especially for longer term stays!