moreover, barista did not recompile assets until we touched / saved / modified the file.
We do not have direct access to production system, so all the bug reports are sent in JS, and we need to figure out how things happened and sometimes it was quite difficult to locate a precise place where it occurred.
now, we have to compile everything and package js files when preparing an updating version of software (again, no SSH connection, no internet connection, only tarball / zip update packages).
and, in general: even though everyone says that CS handles everything that JS does plus more, we found that it's easier to handle factories, mixins, scopes, inheritance and more with plain JS. it was always easier to read and understand, and no overhead for development or production, felt more natural. classes are not something we missed in JS, and comprehensions stuff seemed more like a syntax sugar, not something we really missed.
So - it added a complexity and made people to use CS features instead of things that fit more naturally to JS ecosystem. We've had several issues with syntax (e.q. hash assigned to a variable with a function inside or smth like that), but we worked around them on early stage.