I use some very large projects with hundreds of phrases. There are two big disadvantages at the moment:
If a phrase is used several times, it is necessary to define the translations for each of it. It would help if there is something simple like search&replace. But a better solution is welcome. It is exhausting to repeat 20 times the translation of the phrase "customer" or "client" into 3 or more languages.
It is not possible to outsource the work for translation to other people. Please give us something to import-/export the phrases. If we need 4 translations with 500 words, I need more time to put translations into the language editor, than I need for coding the whole project.