Pros
SAS has a great reputation in the analytics space, so its good for your CV. A good place to go as a graduate, you will learn a lot, but make sure to leave within 3 years or you will drop too far behind the rest of the industry. If you are further in your career then think hard before you join. The pension is good, although make sure to negotiate a good entry salary, its unlikely that you will get a significant raise once you are in.
Cons
SAS technology is outdated, by a long way. I know that there are efforts to close the gap between SAS and free open source technologies that are 5 years old, but the gap is there and it looks like its increasing year on year. Your experience of SAS UK will vary greatly from function to function. Professional Services roles are terrible, there is no work-life balance at all, no sense of community, and no real sense that the organisation as a whole values you at all. Presales is full of folks that have been there too long and have very little knowledge of the competing technologies in the space,so if you join do not expect to learn anything newer and be prepared to have any good ideas beaten out of you. If you have an office bound role in HR or finance then you will have a great work-life balance and a really great work experience - check out what the back office functions say in the other reviews - nothing but positivity... Without the pension the benefits are pretty much the average for the industry, (albeit with a salary thats well behind the industry) although the folks that work at SAS UK have been there for so long they still view the benefits as amazing. There is no career progression, unless you play politics and a more senior role is created for you. Simply put employees in the middle management roles stay too long, meaning that younger employees have no where to go. To add to this the top management roles are always recruited from outside, so the middle managers have no where to go. Essentially this adds to the malaise of having no real view of the outside world and very little innovation. SAS UK had an egalitarian culture - with the revolving door of new senior managers at the top of SAS UK, that has gone, although most folks have been there for so long, there are like the proverbial frogs boiling in water - they haven't realised its not there any more.