We stayed in the flat for more than a week over Christmas and had a great time.
The check-in was quick and easy, we were met by a colleague of Andrea, given the keys and explained everything around the flat and a bit about Malaga. Before and during our stay, communication with the host was flawless, they even ask if all is good from time to time and offer to help if needed. I found that Andrea goes out of his way to make the guests feel welcome.
The flat is centrally located, on a small and quiet pedestrian street. For example, Plaza de la Constitución is 6 minutes walk away, the beach 20 min away. Supermarkets, bars, restaurants etc. are plentiful in the area. Although being quite small, you'll find everything you need inside and it's quite comfy. There's a small kitchenette for preparing some breakfast and such, enough eating space and a small couch with quite a large TV in front of it. The Wi-Fi works very good. In December we had to heat a bit, the AC did the job well. What bothered us a little bit was the fact that the flat is quite dark - the windows face towards a tiny interior courtyard, so there's not much natural light coming in. However, I believe that this actually becomes an advantage during the hot summer months.
Would recommend this place to a friend, even for longer stays, since the flat has all the amenities one needs.