I stayed with Valentina for about 2 weeks and really felt at home here. She's a warm, helpful person who doesn't just rent a place but welcomes you and helps you out. We talked a lot, went on small trips, went out partying, etc. So not just a place to stay, but a home!
Barrio Italia is also, in my opinion, the best neighbourhood to live in Santiago. It's calm, safe and has lots of small shops, restaurants, bars,... The apartment is close to a bus station and a 15 min walk of the metro station.