Staying at Alonso's place was a great experience. It's a modern studio with killer views over the mountains. It's in the heart of Las Condes which is a very safe neighborhood (even though I went in the middle of the Chilean protests). The check-in was super easy since the keys were waiting for me with the concierge. Would gladly stay again.
PS. It may not be the quietest place in Santiago at night since the area is lively. But nothing problematic, just the feel of a large city underneath.