The Refugio Cochamo is really fabulous and we loved our experience staying in the dorms there. Since you can rent a bed and sleeping bags, you just need to bring clothing and a toothbrush! It’s definitely worth booking in advance since there is limited space, and also worth carrying in a good amount of snacks (and maybe a box of wine). The owners' philosophy is to create a comfortable place for people to hang out with a lot of options as well as a good place for camping, but give everyone the space to do what they want and explore however they want to explore, sans tours or guides.
The 4 1/2 hour hike in to the Refugio is super pretty and quite easy, especially if (like us) you just bring daypacks. You go through various sections of beautiful forests, pampas (grasslands), horse trails, and cross little streams and bogs and wooden logs and bridges. At certain places, you can see or even climb down to the crystalline water of the Cochamo River, or see the giant rock domes that look out over the area, impressively overseeing the landscape. The instructions on the Refugio's website are surprisingly clear, and worth printing out or saving to your phone to peek at midway through.
Apparently this area is being touted as “South America’s undiscovered Yosemite” and “the next Torres del Paine” (to note, I think you can hike through to Argentina here now if you bring camping gear). I don’t know how it compares, but it is epically beautiful and in a largely untrodden area. On the hike in, we saw maybe 6 people hiking out, plus 2 locals with some bulls, horses, and sheep. Other than that, it was just us and the tabanos (these huge flies that appear for a few weeks each year).