I have been weary of the Julia pitch which was basically "lets brew R, Python, and Matlab (all >20 years old with massive and unrivalled ecosystems and all serving their purposes very well, thank you) into one "new" language and put a nice logo on it". How is this language seriously the leap forward that one needs to abandon the current awesome toolsets, with all their battle tested libraries, other than a nebulous "speed" argument which in many cases, judging by the comments and my own experience in financial data matrix operations, is not even fully accurate? Ready to be persuaded otherwise if I can be shown that other than "speed" there are hefty reasons to move from Python and abandon the almost endless choice of richly varied tools that I have at my disposal already.