Despite being the Sage fanboy in the thread, I have to admit that all the use I've seen of Sage has been academic or experimental; I haven't heard of anyone usi

Despite being the Sage fanboy in the thread, I have to admit that all the use I've seen of Sage has been academic or experimental; I haven't heard of anyone using Sage for statistics in any context, and not for quants or actuarial science or anything of the sort. I'd suggest that Sage is likely less good for those uses since Sage is good at the kinds of things you're likely to find academics use Sage for (e.g. tons of discrete math and most things cryptography). Secondly, since there's very little pressure for high-end uses of commercial packages to worry about the licensing cost of a mathematics package like JMP or Mathematica.