My favorite part about the place is the location. It's perfect, within walking distance to pretty much everything, el Zocalo, Templo Mayor, Palacio de Bellas Artes, etc. There's also an Oxxo, bakery, pharmacy, and restaurants within one block. The apartment is really nice, it's very roomy, exactly as described. My only complaints are that you need a card to get in and out of the building and you only get one card, so when you go out you have to go out with your whole group. The doorman is very nice and available most of the time, but I really didn't like having to bother him, especially if we were coming back late at night. Also, the apartment at night can be loud, not just because it is in the middle of downtown, but also because the walls are thin and you can hear the neighbors watching TV all night.
One recommendation: Near the corner of Calle 5 de Febrero and Calle Regina, across from the Oxxo there is a tiny little hole in the wall place that opens at night with the best quesadillas I had in Mexico city. I believe it's called Las Escaleras.