Pros
money, smart people, money. benefits you would normally expect are all there (insurance, vacation, bonus, stocks, tuition reimbursement, etc). flexible work schedules (see why below in the Cons).
Cons
We have an annual company-internal technology conference, and this year it is being held in Las Vegas. Despite a lot of employees being invited to attend, ultimately a lot of people can't because their bosses won't let them due to other work. We also have some celebration events maybe twice a year, usually held in the company parking lot. Despite the fact that it's held during the work week maybe from 11am to 4pm, people come for lunch and leave to go back to work immediately afterwards and end up having to stay extra long due to the hour they spend their during lunch. We have all-hands meetings once a quarter, yet at the end of the meetings at 5pm, even though the executives tell everyone to go home and have a good weekend, everybody really just has to return back to work and work extra hours because of the time spent at the meetings. Be prepared to often spend 80+ hours working in a week, and having to work >12 hours each day of Saturday and Sunday.