Pros
As a boomerang employee (one who left and then returned), I know what it is like to miss working for SAS. SAS has top-notch employees who work hard and enjoy working with each other. The benefits are outstanding (best health plan I've seen) and the overall working environment is flexible and fun. I work from home, so I don't get all of the benefits of working out of the Cary headquarters, but the large degree of autonomy, respect from my manager, and liberal travel policies make working here a great experience.
Kontras
It is tough to come up with any cons for working at SAS Institute. But there are a few minor things that can be improved. The only thing that would ever cause me to leave SAS is the salary. In fact, that is precisely why I left - a 30% increase in salary. But salary isn't everything and I was willing to take a bit of a pay cut to return to SAS. Nevertheless, SAS does a poor job of using salary as a motivator. Raises are only given for merit and only once a year. Promotions are also done at the same time. So, if you missed your opportunity for a raise or promotion, you'll have to wait for next year. Also, the bonus program tends to change every year and it is not usually announced until mid-year at the earliest. SAS has shown improvement in the bonus area over the past 10 years, though. Management tends to be clique-ish and has eliteist overtones. For group meetings, management always gets to stay at the Umstead - a 5 star hotel, while staff must stay at the Embassy Suites, Sheraton or some other lower-grade hotel.