The very nice hosts did write a reminder to only ring the doorbell on the correct house (there are two with the same number, in parallel rows, and many guests have gone to the wrong house, as I did). It depends on from which direction you arrive whether this is obvious or not. I found it difficult to find the right house in spite of the clear instructions only because I arrived from the "wrong" direction, in the dark, but got the doorbell message in time.
Also, it is true that the bathroom lock does not work, but there is a sign you hang on the door (a temporary measure until the lock is repaired) and the hosts have proven to be perfectly trustworthy and considerate.
I would stay at Phuong's & Martin's again.