Alex was an excellent host, always happy to help and came over quickly to resolve any issues. He speaks English well.
The apartment itself was on the 10th floor, there were lifts and security as well as two people who serviced the apartments who were around a lot downstairs and were friendly. We travelled with our children and felt safe both in the apartment and the nearby neighbourhood where there were very few tourists and people were generally friendly. (We didn't let them on the balcony though!)
There was a very large park about 5-10 minutes walk away which was nice to get out and stretch your legs as well as take the kids to the playgrounds there, visit the large museum, explore the weekend market or browse the book shops, there were also various exercise classes taking place outdoors and an observatory that offered weekend star gazing nights.
The apartment is located on one of the main streets of Buenos Aires so everything you need is nearby from laundrys to supermarkets and restaurants to the local buses (insanely cheap- make sure Alex helps you get a sube card) and one block from an underground (subte) station so you can easily get anywhere at all in the city and surrounding areas, however, it also means it is very loud so make sure you bring ear plugs!
We felt like we were staying in a local home, the apartment felt very authentic, providing a more immersive experience to experience life in Buenos aires rather than like an air bnb set up for tourists. It was very affordably priced for 3 bedrooms, a large living space, a kitchen and 2 bathrooms, we did need to buy a few items to make cooking achievable (which we left for future guests) although I would still say other guests may need to do the same but it was still far cheaper than booking somewhere else.
The rooms were not laid out or as cosy looking as in the photos and there were less TVs and far less kitchen equipment than suggested but the beds were comfortable and Alex provided extra bedding due to the cold. Really for the price you are getting a great deal.