As it goes with every big company, it really all comes to your department, your team, and your manager, so let me break each one down...
Strike 1 - Department:
My dept is fairly new. It's getting more recognition, but still new. Because it's trying to make a name for itself, often times that means other departments feel threatened so you start to have this mean-girl culture where the claws come out, esp. when you do what 2 other departments also do but your claim is that you're best at what you do.
Strike 2 - Team:
Most of the team members were old colleagues and knew each other from a previous positions. So they're kinda chummy... but not really. On the surface, everyone is polite but when the doors close, the mask comes off. Internally each group is confused what they're responsible for.. and passive aggressively fight among themselves on who did what, who owns what, who calls what shots (You start to think if there are hidden cameras and if it is soon to be aired on Bravo). Sure you have pockets of normal and nice but those are rare (and won't make for good TV).
Strike 3: Manager aka M.F.H aka Manager From Hell
Oh boy, where do I start?!? By the time I resigned, I was the last man standing, the lone wolf. Now, one would deduce that if a manager can't hold on to any direct reports, there must be something wrong with the manager. Right? right!?!? How can a manager announce to the whole team that you realized one of your new hires was a mistake on his first day when he didn't answer a question to your satisfaction? That question should have been asked during the interview!! Ok.... I digress. To sum, MFH is an insecure, manipulative, power-tripping, overbearing control freak.
So after 3 strikes, it's time to get out!! It took me a little over a year to realize how bad this place is. I finally left after 2 years, but it really was 2 years too long.
My advice to others is to join at your own risk. Everyone is doing to have a different experience and its largely dependent on the above factors (obviously).