I highly recommend staying at Josefina's. the apartment is neat and well taken care of. it's right next to the metro and always felt safe with the door man. It was very clean.
At the side, there are little convenient restaurants if you are in a pinch.
Also, the view was amazing. I know one review said that smog ruined the view for them, but I did not at all find that to be the case. There is smog in Santiago, but only at some points of the day and the view was still gorgeous.