This is a pretty special jacket, so I think a lot of the bad reviews have to do with the expectations of the jacket. This thing is absurdly breathable, which means it's great for some things and bad for others. For wearing alone as your outer layer walking around town mid-winter... bad, it's going to let the air in and not keep you very warm at all. But for wearing while hiking, skiing, running, etc. in cold weather where you need some warmth, but would rapidly over heat in a traditional insulated jacket... it is incredible.
To be clear, I still use this as my go-to around town jacket for fall and spring, but mid-winter you need to either add a shell over it or grab a normal puffy.
The primary reason I bought this though, and the purpose it serves that makes it worth every penny to me, is for ski touring in the winter. Every other insulated jacket I ever owned I had to remove and put in my back at some point on my ski tour because even on the coldest days they would make me sweat. This jacket breathes so well that I can keep it on and fully zipped on most tours without getting excessively sweaty. Not only does that mean less over-heating on the hike, but I stay dry so I don't get as cold at the top of the hike either. Then I throw my shell on for the ski down, and with a shell over it this jacket is plenty warm.
If you are just looking for a more casual jacket to wear around all winter, Patagonia has better offerings like the hi-loft down hoody (which is what I grab when it gets too cold for the nano-air).