There are indeed frustrating lags due to JIT, but they have got better lately & are being worked on -- if I understand right this is now one of the priorities, after focusing on getting the breaking changes done before 1.0.

Here's how long a vector of 5 random numbers takes, after a cold start, on 1.1:

    $ julia -e '@time rand(5)'
    0.054343 seconds (121.03 k allocations: 6.219 MiB)