We really enjoyed our stay here. The location is great, a short walk into the heart of Barrio Alto but in the interesting area of Principe Real. Tita was simply a brilliant host. I have never had so many great recommendations for places, and all are things you don't read about in the standard books. Communication was second to none as she messaged us the day we arrived and during our trip to make sure we were ok. She also kindly rearranged her day to let us check in earlier than what we said we would.
The apartment is lovely. It is surprisingly quiet given that it is on a busy street (don't let that put you off, once all of the windows and shutters are closed, you don't hear it), well equipped and easy to get to from the metro. Footsteps from upstairs are quite loud, but you are in an apartment with people above and below you, so that has to be expected. It didn't disturb our sleep though. We would have liked a few more pillows, as you only get one each and they are quite hard, but that is a personal preference!
All in all a great trip and a great apartment. We would not hesitate to come back.