Mito Casa was absolutely delightful. First, the bad parts: the floorboards were squeaky, but I found it charming. Also, the Wi-Fi was too slow to stream video, but I didn't go to Santiago to watch Netflix.
The central location is great, the house decor was absolutely charming, and MY BATHROOM HAD HEATED FLOOR TILES. The service also went above and beyond - I mentioned that I needed some emergency sugar on-hand due to my diabetes, and not only did they provide me with boxed juices gratis, they also gave me some extra sugary snacks and refreshments to keep me going on the road at check out time.
I unreservedly recommend staying at Mito Casa when visiting Santiago.