Vantaggi
I've had the good fortune to have fantastic managers. They are friendly and supportive (assuming you do your job well). My coworkers are also very intelligent and competent. Depending on your area of the company, you may be able to work close to 35 hours per week. SAS offers a lot of free internal training on SAS and other topics. Benefits are great.
Svantaggi
The famous 35 hour work week is not universal--some areas of the company require much longer work weeks. It is difficult to get funding for outside training. The pay is lower than for most competitors, and competition from open source software is cutting into raises and bonuses. Young professionals may enjoy the environment less, as the workforce is older and many of the benefits are geared toward employees with children. Long term prospects are less than ideal due to the reduction in raises and bonuses and a lack of upward mobility.