We stayed in Peter's room for four nights. The location is incredible for the price, however this room seemed to be the "runt of the litter" out of Peters other listings.
I would rate the location as 6 stars; you're walkable to everything from The British Museum to Covent Garden. Peter is also very helpful and fast with his communications. The room had ample power outlets.
The bad; the room is wedged between another bedroom and bathroom with shared, thin walls. The location is not a private home but more hostel like (completely fine, but that's not apparent in the description).
You share the bathroom with two other rooms and the plumbing runs through a conduit in this room making loud clicking noises. You can clearly make out conversations from the neighboring room and the room below you.
Even with ear plugs we were woken up multiple times by normal conversations from other guests.
The window shown in the photo is into a closet - the closet, in turn, has a smaller window to a wall. Odd, but not an issue.
Reading the reviews for the other rooms that were proper studios (4-6?), each on their own floor with a private toilet I would recommend one of those highly as the location for price.
The location is great and those don't seem to suffer from the shared walls and bathroom issues.
Unless you're a very heavy sleeper, bring good ear plugs for this room; alternatively I think room number 1 (we were in 2) has a proper window to the street (street noise would have been preferable) and isn't right next to the bathroom so you might fare better.