What really annoyed me about array languages is that idiomatic code is nearly impossible to follow after a month, so I ended up aliasing many of the commands to more verbose alternatives and using longer traditional constructs like IF-THEN-ELSE.
That pretty much turned the language into weird-C-limited-to-binary-functions-with-an-array-stdlib, which kind of defeated the point.
[1] http://www.jsoftware.com/
[2] https://github.com/ngn/aplI've not made any speed comparisons, but maybe you can give APL, J, Julia and SAC a bench? That would be neat! A simple hello world like example, for example using the same FFT algorithm, or "addition" loop would be enough.