An interesting question is how smart Nest and others have become about understanding the baseboard heating. In my house, where everything is forced-air (heating and A/C), it's simple for the controller. But when you've got to open and close valves, heating still happens after the valve is closed, so a really good thermostat would need to figure that out.

For contrast, when I was renting a place in winter that had sub-floor piped water heating and a "traditional" thermostat, I ended up just setting it to a constant temperature 24/7 because it took forever to warm up from off, and the controller wasn't particularly smart about it. (And because I wasn't paying for the heating bill...)