SUMMARY:
While the room comes at an appealing price and the bedroom is comfortable, because of the very poor (and possibly unsafe) state of the bathroom I cannot recommend that anyone stay in the apartment in its current state, except perhaps if they intend to find a nearby gym to shower in and are prepared to grin and bear it when using the toilet.
DETAILS:
Lewis was polite up until and including my stay, and the bedroom was good, with a comfortable bed. However, there appeared to be a major leak above the bathroom ceiling, to the point where (1) there was water dripping down over the toilet, and (2) there was a very large water stain covering a significant proportion of the ceiling, with what appeared to be mold. The bath was also noticeably dirty (and there was no shower, though this can reasonably be inferred from the photos of the apartment).
Because of the poor (and possibly unsafe) state of the bathroom, after my first night I tried to cancel the last two nights of my scheduled four-night stay--I had already stayed past check-out time on the second day, so I thought it'd only be fair for him to be paid for that night as well. Lewis has yet to respond to my request in any form.
After that first night, I ended up spending the rest of my time in London staying with a friend and sleeping on his couch. It was a considerable improvement, as would have been a hostel.