"You get what you pay for" is usually a good adage, but it doesn't apply here— in the good way, for once. I came expecting a simple-but-sufficient and cheap place where I could sleep but otherwise only come back to when not out and about on my holiday, but I was very pleasantly surprised compared to other accommodations I've had.
William is a very helpful, open-minded guy, and generally very hospitable guy which was a great boon to me since travelling alone isn't something I'm quite used to and am still a little scared of, so this was quite a welcome boon (the same goes for his current lodger). Checking in and out was easy and smooth with a tour around the house and an explanation of all that matters.
As for the place itself, I would say there's quite literally nothing wrong with it: All the shared amenities are there, they're clean and well-maintained. The bedroom is perfectly nice and suitable with a lock for privacy, a direct entrance to outdoors, and a perfectly sized and soft bed to crash in after a day out. Only drawback is that it's a bit of the walk to the biggest supermarkets around, but public transit and such are still quite close, which makes even that mostly a non-problem.
If you're looking for a cheap and perfectly serviceable stay, book here. I know I personally won't hesitate to book again next time I'm in London.