We stayed for a week.
Positives: fantastic view, quiet, close to park and grocery store, walking distance to major cultural attractions and good restaurants.
Negatives: no bathroom soap on day of arrival, TV from the 90's did not work, furniture is uniformly uncomfortable, only a single wine glass... generally not a high degree of livability. We did not meet Ariel but he was responsive via email.
I think a few days in this apartment would be great to enjoy the sunsets. Longer than that however and the general lack of comfort will begin to weigh in.