Pros
Stability, job security. It's very unlikely that people are fired or "let go" in Japan. They simply "move" people to the most mundane positions/teams in the hope that they will just quit. (Just google "japan forcing-out rooms"). I even know of a woman who is a complete alcoholic and pretty much just sleeps at her desk all day, but no one can fire her. Japanese rules! So if that appeals to you then it could be classed as a "pro". Lots of nice people work here. Genuinely nice and polite people - even upper management. Not so much overtime. This was a concern for me because we've all heard of those crazy hours that the Japanese work, but actually in my team we do a 10 - 6:30 day. Occasionally people stay a bit later but its rare. Other teams (engineers & developers) seem to do longer hours but I'm not sure. Canteen/food court - meals are generally good with lots of choice and basically quite cheap (yes, not free). Typically a lunch meal comes to 600 - 800 yen. You can sleep anywhere and at anytime. Seriously, people sleep at their desks, in meetings (oh yes!), in the communal areas...pretty much anywhere. I've never done this, but it seems acceptable.
Cons
The work environment and atmosphere are torture. Seriously, it is not a surprise that people commit suicide as much as they do (oh yes they really do). This isn't a problem specific to Sony HQ of course, many Japanese companies suffer from this. But honestly, the office space is cramped, dark, messy, overcrowded, outdated and very bleak. Hard to stay positive some days! The "salaryman" salaries are low in Japan. Seriously, nothing compared to EU or US. Plus there are no benefits - seriously, nothing. No discounts on PS (or Sony products), no freebies, no launch parties, no Xmas parties (well, we get a 2 hour bingo session with a few drinks and snacks), no training to non-Japanese, no off-site team-building...we even pay individually when our manager calls for a team meal & drinks in the evening. You get your salary, you get your bonus and that's it. Very little chance for career development. Japanese people work for years and years until they are "the right age" just to finally get promoted to team leader of manager. There is very little internal movement opportunities for non-Japanese. 8 months ago I contacted HR to express my interest in broadening my career by moving to a new team or at least hearing of any internal opportunities, after a brief response confirming that they understood my request I never heard from them again. Toilets- there are 26 floors and each floor has about 300+ people (mostly men), yet there are just 9 cubicles on each floor. People actually queue up and wait outside the cubicles. There's a clock-in / clock-out system. You know how you see in old movies of factory workers punching their cards in and out? Well, now its digital but basically the same. And if you are not making core hours for the month then you are forced to use your annual holiday. Seriously, I missed core hours by 1 minute once - yes, just 1 minute - and I was told by HR that I must use half a day holiday.