We live in a place that has 2 right now We've lived in this building before and there are only one or two units that don't have this heating. Ours is controlled by the landlord who runs his business in the bottom portion of the building. It's coal heat and he physically turns it on 2 times a day. He has a thermostat for it that gets turned on later this month or whenever temps are consistently below 50 (which ever happens first). It's set to kick on itself once it drops below 50 and turn off at 90. One drawback is that the thermostat is for the business so 90 downstairs is generally much hotter upstairs.
Ours get HOT. The one in our kitchen (one there and the other is in the living room) gets hot enough the steam valve does whistle the majority of the time. Our other one doesn't.
Ours run hot enough that we usually keep a window cracked all throughout the cold months to help regulate the heat. I did try turning off the one in the kitchen (since it ran the hottest and the kitchen is one of the smaller rooms so it bakes and wasn't safe IMO) but it seemed to mess with the entire set up as a whole. Not sure if mine are tied to each other but I did end up turning it back on.
Our apartment is small enough (600ish sq ft) that we don't get the cold extreme often associated with the slow warm up. We do, however, get the high heats that take longer to get to a comfy temp. Ours do knock when they first turn on but only for a minute or so. I kind of like it for some reason.
We like it though. Our landlord's business is a pump service and he has 24 hour call so if we need an extra kick of heat we can call him and he will happily come out. He also doesn't care if we have every window open in the house to help regulate and told me the other day he likes doing it himself.
I don't think we'd complain much anyhow. We don't have to pay for it.
Only real drawback to us is potential safety issues with kids. Mine are old enough and can remember living here before that we don't touch or play around them once it gets cold. Ours put off enough that getting too close is uncomfy anyway. For kids who aren't familiar with our house or are younger (such as crawlers) we are a bit more paranoid. The base on ours don't run as hot so it wouldn't be a stretch of the imagination to get a curious crawler over there and reaching out to pull up before noticing the temp. So far though, we haven't had an issue. Most kids seem to catch on fast.
Oh and our winters are seriously freezing! The schools had to drop their "snow day" requirements because the former temp was basically our average for the whole season.
ETA: Because this post isn't nearly long enough.
Our building is OLD....1910ish (I can't remember the exact year stamp on the front of the building right now). It used to be an opera house for the town so the apartments are actually conversions of various rooms that were here before. We have leaky windows like mad. Ours heat wonderfully. We don't need to shut doors or block off areas with less use or anything like that. Like I said though, ours is coal based heat. Everyone else who has posted here seems to have gas. I have no experience with that.