Loved our stay. The place is clean and hip, very comfortable to stay, and could easily be a longer term location if you're needing to stay for a couple of weeks.
Both of the spiral stairs are a bit tight if you're a larger frame like I am, and wasn't a good idea to try to get baggage up/down.
The kitchen was well appointed and beautiful with the windows and sunshine in the morning.
The neighborhood is a pinch hard, but nothing off-putting to speak off. Everyone seemed very nice and quite. There's an excellent breakfast spot on the building corner, and a very friendly wine bar a block+ down the street. They have happy hours on F/Sa nights (sad we missed it).
I wouldn't suggest early & light sleepers as it's a little loud on the street with the neighborhood pub on the next block. I also wouldn't suggest anyone who has mobility restrictions, as the stairs are narrow and a little steep. We were lucky to have good weather on our trip, but if you come when it's cold I would be prepared as the flat will get chilly unless you're diligent with the heaters.
The underground was our primary mode of travel, and it's right about a half mile walk to either Bethnal Green (Center Line/Red) or Stepney Green (Hammersmith Line/Orange, and Circle Line/Yellow) and don't worry about the times, the underground trains run so frequently that they'll be very easy to hop on whenever you arrive. It was very easy to get around, and we didn't even try the busses!
Overall we really enjoyed our stay and we will be recommending it to our friends when they're in London!