Absolutely lovely stay! The apartment is just as described, beautiful, classic, and in an excellent, central location bordering Parque Mexico (be sure to check out the dog school in the mornings if you can!) We did not interact with Agustín at all during our stay, but communication prior to check-in was fantastic, and I'm sure it would have been the same if needed.
One quick note - the apartment does not appear to be heated (fairly common in Mexico) so if traveling in winter it might feel a little cold at times. We used the space heater provided during our stay and were totally fine, but others may prefer a more centralized system.
Overall, very highly recommend!