I was very surprised to find Carla's place to be much less nice than the other reviews. The two main downsides of this Airbnb that are not at all accurately painted in most of the reviews are:
1) The SMELL / AIR is incredibly musty and unpleasant. Once you walk in from the dusty street, it is like walking into a wall. You'll notice that reviews mention there are no windows -- they do not mention the poor ventilation. If you want any ventilation, you have to go on the roof and unlock the padlock of 3 small skylights (and close them at night, to feel safe). You do get used to it over time when inside, but for anyone with asthmatic issues, it's a big problem.
2) The NOISE is extremely loud. You are literally right on a very busy street, the sidewalk is the other side of the bedroom window -- even if you wear earplugs at night, the house reverberates with the sound and vibrations of passing cars. I work from home and found it impossible to stay in the apartment from the noise.
I also was surprised by my unfortunate interactions with Carla. I had booked this place less than 24 hours in advance (for 2 weeks) due to another place falling through -- I'd asked for an early check-in, which she was happy to accommodate, but then when I notified her 1.5 hours in advance that my companion's flight had been changed and I would need to come later, Carla was very rude to me. After I told her I felt she was being unprofessional and trusted her to find a solution, she became much kinder and arranged someone to meet me.
I was excited to get to the house, but upon entry immediately noticed how much worse the mustiness and the noise were than expected. I'd read the reviews closely, so was very disappointed. The design is as nice as it looks in the photos, but I could tell immediately from the air and the noise that I wouldn't be comfortable staying there.
I contacted Carla almost immediately to tell her, offering that since I'd booked less than 24 hours in advance, I could leave immediately and just compensate for the cleaning service. I felt it would be better for both of us, since I knew I'd have a bad experience. She refused to be of service, and asked me to have Airbnb find a solution. But, when she spoke to Airbnb she said I could not leave without paying for a minimum of 5 nights.
When I explained to her that those minimum payments are in place to cover opportunity costs to hosts (and that since I'd booked less than 24 hours in advance, there should be a much lower opportunity cost), she was very firm that she was unwilling to take less. So -- I stayed five nights, slept very poorly, and unfortunately have to write my first negative review on Airbnb since starting to use the platform almost ten years ago.

I will say that I made several requests of Carla related to the apartment -- water (since there was none upon entry - unusual in Mexico), a mat to cover a big grate on the floor, a non-rusty salt shaker -- and she was swift in getting me those things.