Communication with Ali was very good - he replied to my messages in a couple of minutes. The location was very close to Shadwell train station. The flat's room temperature was nice and warm, which, considering I was travelling on one of the chilliest day of the year, was very important. Checkout was very easy.
The Tower Bridge is a walking distance away. There are several supermarkets near by (Tesco, Waitrose and Co-Op)
A few minuses I've noticed: The rubbish bin in my room wasn't empty when I checked in; there were no tissue napkins in the room or in the kitchen; the shower water was cold (it took several minutes to become acceptable) and the shower water pressure was low; because the flat was so close to the train station and railway you could hear the trains passing by at night and early morning.
Overall, it was an ok stay for an overnight sleep.