I regularly produce data sets that are too big for RAM, and not having to worry about that in SAS was a luxury. I'd say SAS's two big "Killer Features" are the

I regularly produce data sets that are too big for RAM, and not having to worry about that in SAS was a luxury. I'd say SAS's two big "Killer Features" are the DATA step and SAS Press. I still have yet to find R or Python nearly as pleasant to work with for manipulating the data set itself when compared to SAS, and the SAS Press is excellent at putting out books detailing a given type of analysis, and how to implement it in SAS. I still turn to them for basic references even when not using SAS.