We stayed here for three weeks over Dec/Jan 2016/7 (couple with 10-year old). The 1-bedroom apartment is well fitted out, with an excellent kitchen and good furniture throughout. Our son loved the fold-out sofa bed, and enjoyed setting it up each day.
The apartment was a little snug for three people, but we managed fine. It would possibly be more suited for a couple or individual, especially for a longer stay.
The bathroom (shower only) was compact, but lots of hot water and a really good shower was very welcoming after a long day of sightseeing! The bedroom is a good size, and has two wardrobes with plenty of storage space. My husband is a light sleeper, so as the bedroom is right on the street he sometimes struggled with street sounds. I am a bit of a heavier sleeper and didn't have many issues, though. There is a pub two doors down, however this was under renovation during our stay. There are (at least) 4 apartments in the building, this apartment is on the ground floor. While the trains run behind the building, it was barely audible, even when in the bathroom. This apartment has a small washing machine, which was very useful.
The location is very good - only 5 minutes' walk from Southwark Station and 10-15 minutes from Waterloo Station. Most nights I took the tube into the city to see a show, and it was incredibly easy (get an Oyster card!). There are multiple Tesco and Sainsburys supermarkets within 2-10 minutes walk. The Borough Markets, local (good) shopping, London Eye, Globe Theatre, the Thames, The Old Vic, The Young Vic, BFI, National Theatre, Tate Modern, London Bridge and much more all within 10-20 minutes walk of the front door.
Janet was responsive to emails and messages, even when we had a little trouble getting in initially (our fault), and provided fresh linen halfway through our stay. We would recommend to a couple or single person and would certainly consider returning here in future.