I find bugs and unintuitive behavior a lot when using Julia. Often it requires me searching the mailing list or Stack Overflow to figure out "idiomatic" Julia code when this really should be in the documentation (who knew that a matrix operation A += B allocates new memory for A each time?) And I think global variables should just be removed altogether, as many problems as they cause. I commonly find myself thinking "There's no way that someone new to Julia would know you're supposed to do it this way", whereas with Python or even C, that's not the case.
But I think the language has a lot of promise, and the language design is really slick and well put together: powerful macros, a nice type system, multiple dispatch, clean code when you don't need performance but lots of additional decorations you can add when you do (devectorization, @parallel, @inbounds, @simd, type annotations).
Remember that Julia is only at dev version 0.4. The author of the article complains about breaking backwards compatibility on an almost daily basis by removing or changing things. At this early stage, I see absolutely nothing wrong with this. I'm tired of languages that have unintuitive and quirky (stupid) ways of doing things just in order to not break existing code. C++, for instance, is abhorrent to me. How many pages is the standard??
At the moment, Julia has a steep learning curve if you want high-performance code. But once you know what you're doing, it's easy to get it running at the level of C. Plus, features like viewing the AST, or the LLVM and native assembly representation of the code are handy for debugging.