This flat has a fantastic location. Right next to the Borough tube station as well as bus stops. I highly recommend checking out this place for a large variety of food options: https://www.mercatometropolitano.com/mmarketplace/elephant-and-castle/ We unfortunately didn't discover it until near the end of our trip.
The unit does have two USB outlets, but they are rather low amperage (takes a long time to charge). I definitely recommend you plan on bringing a converter for your plug-type. Lisa had left two for us and we made heavy use of them - especially since I mistakenly brought my EU converts and not the UK ones...