When I had to go in, the gave me an appointment at 2 PM, then had me waiting for an hour because the person handling my case was in a meeting.
it was kind of weird because then other customers arrived, but they had to go to different windows than mine (they were citizens, I am a LPR) so I waited and waited. Then I asked the security (which was comprised of two locals speaking Spanish only, and my Spanish was basic) if I missed something. They started telling me that I need an appointment, which I had (but I had no printer to print the appointment email).
It was all very messy, but the guy that finally showed up was SOOOO nice that made up for everything*.
*I am used to late and rude Italian staff, so just one thing different makes me forget the other.