This reminds me of my own experience, but we were all three groups rammed together in the same little space. Fun times.
I was a "voluntary" comitee, in that they offered to get a judge to commit me and I figured going along with it would reflect better if anyone digs this up on my record. Only one actual interment though, for less than a week.
From what I could glean it seemed that (for many people) a big part of the reason to put anyone there was to get them on medication, wait long enough for the meds to take effect, and keep an eye on them long enough to address any serious sideeffects. Not so for everyone of course, but for a lot of people. My interactions with the doctor were very brief and useless; all they had to offer were drugs, and I was fairly stubbornly in the opinion that I wasnt going to take any drugs, and in the end they let me out having swallowed not a single pill.
Some of the technicians were fine, very nice, respectful, sympathetic. At least one I got the impression had an experience being in such a hospital as a patient. One was pretty spiteful, especially against certain patients (it was mutually deserved, from what I observed).
There were visiting hours, some people used them, I did. Time was a little limited but you could get at least an hour, my memory isnt perfect. There was definitly some courtesy as far as privacy with your visitors (could get one of the techs to let you outside even when it wasnt normally scheduled type of thing (but they'd still watch)). Outside of course meaning into our narrow concrete yard with double layered fences the height of two and half men. Not great but what do you expect.
Overall was an interesting experience, I dont really think it had much effect on anything for me directly, but I think it may have been a call to attention to some in my family.