There aren't enough positive words for this place! Practical things first: So clean, quiet, with everything you could possibly need in the space. The shower is amazing, plenty of hot water. Wifi is perfect, and the desk and chair are great if you have to work. The bed is very comfortable! It is a short walk to a small grocery store (10 minutes), the city center with supermarkets, coffee shops, international stores, and places to eat (15 minutes), two parks (10 minutes), and Upney Station (10 mins). From Upney, it's about 30 minutes to the Tower of London and 50 minutes to Westminster, where "Big Ben" is. The trains run very regularly.
Extra positive things: The sunroof was my favorite part of the apartment. You can open it and look outside, and it just lets in nice light. The microwave is also an oven and can bake (I made a homemade quiche). If you have to do laundry, there is a heated dryer rack that dries things much faster. Your hosts are INCREDIBLE! If you are the type of person who just wants to be alone, they completely understand. But if you do like to socialize, they are so warm and welcoming. We had so many good talks (over tea, or a backyard barbecue, or scones), and they taught me a little bit about their passions for baking and the important Caribbean history of rum.
The only drawback is that all of the goodness made it difficult to leave when my stay was up. :)