Pros
Lots of variety and exposure to many types of projects. Solid pay and benefits. High level of professionalism and expectations. Demands both broad and deep understanding of your particular market or product. Despite some structural and cultural challenges, there are a lot of great people working here. Company has a unique, "different than the rest" culture.
Cons
Typical, long salary-man hours. Monoculture: recruits too many sports-types from major Japanese universities. Complete lack of vision in upper management. Company values self-sacrifice (self-destruction?) and group-loyalty over individual performance. No job description, so main working-level people have to do EVERYTHING. Company suffocates itself with lots of unnecessary admin and internal reporting. You will only advance in this company if you are Japanese AND male.