I tried this at a store before buying and instantly liked the feel and look of the chair.
Regarding the comfort - I work a lot from home and work a lot - that is, sometimes 10+ hours in front of a computer. This chair was very hard for the first month of usage, similar to a bike saddle that needs breaking in. My posterior was pretty hard after sitting on this chair. After a month or so, it has become increasingly comfortable and I'm now very happy to use it and sit on it for long hours. I saw that they also sell a specific cushion but I don't think that is necessary, you just need to bear with it.
Regarding the shape, it is described as 日本人向け but I am a gaijin (182cm/75kg). For me, the chair has not been problematic ergonomically. Back support is good and my sit bones fit nicely on the chair too.
Regarding the looks - actually I think it really looks good (I bought the black one). It is small and is not bulky like many office chairs. It is the perfect size for a Japanese apartment. I really appreciate the minimalism of the chair.