I live in a 100+ year old row house in South Philly, and have hot water heat. It is delivered via room radiators.
The radiators are nice for silent, steady heat. I don't understand why, but our house is not dry in the winter like some homes with forced air heating. It is not like the sealed radiators are adding moisture to the air. In the winter, we do allow the moisture from the shower to evaporate into the rest of the house, so perhaps that helps.
There are some down sides to having a boiler for heating. It means the house was not built with ducts that can be used for air conditioning. So a roof top air-conditioner cools the upper level of the house though a duct system that runs though the ceiling of the upper floor. A though-the-wall unit cools the main level. It cost nearly $9000 to replace the roof top air conditioner a few years ago since it is a high efficiency packaged unit (a one piece unit with air ducts going to and from the house), and a crane was required to remove the old air conditioner and move the new unit into place. While I can change the filter, each spring the A/C contractor must use a ladder to get on the roof to do the yearly service check.
When using the heat in winter, since we are not home during weekdays and like it cooler at night, we used a programmable thermostat to make adjustments. This is where hot-water radiator heating systems, which take a long time to heat up, are at a disadvantage. The problem is that most programmable thermostats don't compensate for how radiant heating systems work. They don't turn them on early enough to reach the right temperature in time, or off soon enough to not overshoot the desired temperature. They just shut off the boiler when the set temp is reached. But since the radiators are filled with hot water, they continue to heat the house beyond the desired temperature, resulting in large temperature swings, especially when the temperature has been raised from a lower "away" temperature to a warmer "home" temperature.
Just a couple of days ago I installed a nest thermostat, which is supposed to learn the particulars of our home and radiant heating system, and compensate based on settings and outside temperature. The hope is that it will be able to maintain a comfortable temperature without overshooting the set temperature while we are home, and save energy by automatically going into away mode when we leave.
I do like that it is connected to the internet so we can have remote access. One of the first world problems we recently experienced with our old thermostat was over Thanksgiving when we were away for a couple of days. The temperature was set lower to save energy, but then when we got home to a 55F (13C) house, it took a couple of hours for the house to heat back up. With remote access, we can now tell it ahead of time to warm the house before we arrive.
If anyone has experience with the nest thermostat, I would love to hear about it. I am hoping that it will bring out the best in our radiant heating system.