We enjoyed staying in Doreen's unit for 8 nights. It is really well located.. The size of the unit is really good as well.
There are advantages of having the Tesco Extra (which is a massive supermarket - including alcohol - open 24 hours a day, except on Sunday when it is opened from 11 to 4 or 5), train station, and leisure centre all across the road. And Streatham Common park (a massive parkland) is also located across the road on the other side.
The location was a big plus for us. We paid for 5 day passes at the leisure centre and used it every day. It has a gym, pool, and ice skating (which you have to pay extra for).
There are some good family friendly places to eat located in walking distance from the unit (such as the Holland Tringham hotel).
The unit has a big dining/lounge room, with a good sized dining table. We were here visiting relatives and we had them over for dinner twice, with 8 of us able to sit around the dining table.
Doreen is also very helpful. She offered to do a load of washing for us (which we took her up on and she returned the clothes on the same day). There is no laundry in the unit, but there are laundrettes located close to the unit. Don't trust google for this, as the closest ones weren't listed. There is one on the way to the Holland Tringham hotel, that I used and the lady who works there was lovely and helpful.