To start with the positive:
This is a clean, comfortable, spacious, well-equipped unit in a great location, plus with the cache of having been formerly occupied by Alfred Hitchcock.
I did have several issues however:
1 - After reserving with Airbnb I was requested by the Agency managing the rental to fill out a form which included providing my credit card information. I objected as I don't think this needs to be provided to anyone other than Airbnb. The Agency relented and the listing proceeded.
2 - Given that I arrived in London on an early flight and had nothing to do all day, I requested on several occasions to do an early check-in. The response was that I would have to pay an extra fee (which is fair), but that early check-in could not be confirmed since it depended upon the previous guests' departure and then cleaning (check-out is 11am so this left them 5 hours to clean). They did not respond on whether the fee would be refunded if early check-in was not possible. In the end I checked in at 4pm, but this seemed a little opaque and inflexible.
3 - during my stay I at one point could not lock the patio door. I wrote the Agency immediately and it took them nearly 2 days to address it, meaning my valuables were left in an unlocked apartment. The Agency did send someone over to address it, but then later that night when I returned as soon as I opened the door a screeching alarm went off. It took me a couple minutes to disarm it, but I'm sure it woke up everyone in the building. Good grief.