I stayed a month and with my partner. It's small, cute, a little tight but doable. Good water pressure, the water heater works well. The shower is great! Their hand soap smells delicious, I loved it. They have a water filter which helps a lot since you don't need to buy bottle water. The washing machines are pay machines which need coins. Be careful because they don't specify how much money you need for your loads, so the machine stops before finishing which makes you have to add more coins. The treadmill in the gym doesn't always work well. The small gym is usually empty which is great of you plan to use it. The screen doors were fixed while we were there but still didn't work well so we were not able to use the all balconies. The rooftop has a lot of mosquitos, bring repellant. If you leave the windows open (which is necessary, sometimes), you get mosquitos but the owners were really nice and brought us a mosquito net for the bed, which really helped minimize getting bit at night. The walls and tiny kitchen table are painted white but be very careful because it stains very, very easily (too easily). The good thing is that the owners are super understanding about that and have it worked out. We broke a wine glass and the owners replaced it quickly. They also sent someone over quickly, to fix the tv. Flavia and Mauricio are very quick to respond, they're professional and attentive. The people who work in reception are so kind! They're always there to help, answer any questions, protect you when you come in and out of the building and they also help you check-in /out quickly. The only things I didn't really like were: it's small (which is fine for a few days but not for a month, with another person), the kitchen table is tiny which makes it hard to enjoy a meal together and that the area is not too safe to walk around at night (especially after 9pm) which resulted in me not going out at night or coming home late. That should not be a problem if you come and go with Uber or safe transportation. Another thing to note is that the curtains are pretty sheer so anyone can see you on the street if you have the curtains down with the lights on in the apartment at night. This was shocking for me since I realized the people outside got to see more than I feel comfortable with. If you want privacy at night, you'll need to keep the lights off. During the day, note that if the shades are up: anyone can see you from the street.
I recommend this Airbnb for short stays or to stay on your own for longer stays. It is super close to places of interest in the Historic Center which makes spending your days walking around El Centro, really fun. Again, I would not recommend walking home at night, especially alone, since the specific blocks where the apartment is located are not the safest. I do highly recommend Flavia and Mauricio as Hosts.