My understanding was that Julia gives you the option to write loops explicitly but it doesn't stop you using vector and matrix operations when appropriate, so I'm curious if there are any particular operations that its array implementation are missing?
I think this comment is referencing the fact that as of right now, slicing a julia array creates a copy and not a lightweight "view" of the sliced data. This makes vectorized operations on slices of arrays sometimes faster in numpy than in julia. See https://github.com/JuliaLang/julia/issues/3701.
Note that you already can make view slices, it just isn't the default. As per the issue you linked to, the default will change to views in version 0.3.