Overall a great stay. The number lock is great as it allows for a quick and easy check-in and check out and you don't have to worry about keys. We were also allowed to drop in our bags before the actual check-in and head out to eat while the apartment was cleaned. Raffaele also made sure that we had everything we need and was quick to respond.
De Pijp is also a great neighbourhood with a lot of nice bars and restaurants within short walking distance, definitely worth exploring if staying in there. Centrum can be easily reached with the tram line 4 or by a ~30 min walk. You can also reach the apartment easily by taking a train from Schiphol to either RAI or Centraal station, and then the tram 4 to the apartment. Though going through Centraal takes a bit longer, I would recommend it as you get a good first glimpse of the centrum during the tram trip.