Specifically, from personal experience I strongly ...

Specifically, from personal experience I strongly advise against if you need assistance for a dispute or assistance to obtain amounts not paid by the employer.
If you are not a member they deceive you with the possibility of recovering missed payments and then the absolute darkness, absent communication, every time you want to be informed about a practice you have to make endless files to then be told "no news", I do not reply to emails even for simple communications ...
But if you contact them because you want assistance and you are not registered, they are extremely available ...
I speak on a personal basis but my wife lost a year to recover 3 years of ROL never paid, with all the payrolls in which ROL appeared instead enjoyed while she was present at the workplace ...