We enjoyed our two night stay at Josh's. The location is excellent, only a couple of minutes walk from the tube. We were met (ahead of check in) by an associate of Josh's, who let us in and talked us around. There is an (old!) elevator which we only used when transporting luggage. The room is clean, a good size and comfortable, having a full-size bed and a couch, although there isn't much by way of closet space (rather normal for the age and location of the place). There is access to one bathroom shared by the owner and another AirBnB room, plus a small but well-equipped kitchen.
Unfortunately we didn't meet Josh due to conflicting schedules, but he was very helpful and easy to communicate with via AirBnB. Unlike some of the AirBnBs I have stayed in, he hadn't left much by way of local information - but I suspect this is because he is usually available to communicate this in person. Other minor downsides included loud local construction (not the owner's fault, of course) and an easily-fixable issue with the shower that wasn't really a problem due to our short stay. Overall, we enjoyed our stay, thought the value was reasonable (for London prices!), and would fully recommend.