Armando's place is perfectly located in the middle of downtown Mexico City - across the street from the main central park. It is surrounded by great restaurants, museums, etc. and the subway and metrobus are literally 4 minutes away. It also has great views of the southern part of Mexico City.
The space is nice and comfortable - big and well lit (it does tend to get a bit warm because it is south facing - so, you'll be asked to close the shades). The bed is comfortable (and there are extra pillows in the closet). The shower is great with plenty of force and hot water.
The building is safe - there is are 24 hr. doormen at the entrance. And, every once in a while they ask for your room number and name. But, they are very nice guys.