Having done a lot of Airbnbs at this point, my time at Mark's was a solid three-star experience. It's simple, the check in was beyond easy, Mark was responsive via message. On the downsides, the bed was somewhat uncomfortable, toilets were quite often left dirty by other guests (understand this isn't massively within host control apart from perhaps more frequent cleaners) and it felt a bit sparse with older furniture and decoration - definitely a student house vibe, but this is absolutely fine for the low price paid. The room basically serves its purpose and is well located for Beckenham and surrounds, it helped me between flats so I was fine with that. Perhaps a bit far from central London, if this is the reason you're visiting.