Pros
Extreme stability, literally close to zero chance of getting fired unless you commit a heinous crime. Work-life balance is generally alright for regular non-shift office workers. Temasek-backing.
Cons
People can be astoundingly stupid. There are good people around, but the population is slowly decreasing as they tend to leave after having to deal with the stupidity. There is a huge pool of people who have worked here for 15 years and up, purely because nowhere else would want them. These people aren't just terrible at work, they have terrible personalities as well. The rot within the organisation infects the surrounding healthy areas and causes an exodus of talented and hardworking people. Leadership can get personal instead of objective. Yes-men all around, scrambling to do the next stupid thing that whoever above them has dictated. Leadership insanity includes misuse of company resources for personal benefit; i.e. publication of own books lol.