For starters, waking up and going to bed with that view is worth the stay. The apartment is as it looks in the photos. Everything is very clean, the views from the apartment and from the terrace are splendid.
It's located at the edge of La Lagunilla which is next door to Tepito. Don't let that bring up any worries, we had no issues in term of security. Juan gave us a lot of tips for surrounding neighborhoods. We actually wondered into Tepito, despite host advising not to, but we got tips from a local friend and went in and out without harm. So don't worry about location. Mexico city is a city, and thus you should take the precautions one would take in any city in any country.
The apartment is about 2-3 blocks to el Zocalo and Metropolitan Cathedral. And about 10-15min walk to Palacio de Bellas Artes. On the way to Zocalo you can find AMAZING food. All street food has been the best.
I also worked the entire time I was staying here, and found the terrace a great place to get work done in the mornings.
Juan was the guy who welcomed us to the apartment. He went above and beyond to make sure we felt comfortable and informed. Gave us a lot of tips for navigating the neighborhoods, places to visit, food, etc. He was great!
The doormen are very friendly, as is the maintenance guy who takes care of the building. They all made us feel very welcomed.
Host answered all our questions very fast. Checking in and out was smoothly. I would definitely stay here again.