Hi guys,
I don't know how the language aid works for the PMP exam, but I agree with you that - after studying all the training material in English - I would probably find it harder to sit the exam in Italian. In fact, I must admit that, besides my understanding, I don't really know how the main concepts translate into Italian. This is why I decided to download the Italian version of the PMBOK , just for fun
after having passed my PMP exam
So indeed my recommendation is to go for the English exam, even more so if you practiced your exam simulation in English as well. Sometimes you may find a few questions where you don't know the exact meaning of a word or two, but my experience is that the context always helps, so that it is not crucial to know the meaning of every single word in the question.
If the language aid instead shows you the questions in English, and you need to ask for a translation into (say) Italian whenever needed, then maybe it won't hurt.
In bocca al lupo!
Gabriella