What is the difference between EU and US radiators?
Honeywell does not provide a ton of info, but from the installation manual it would appear that evoHome is assuming each room has its own feed and return pipe, and in addition has its own local valve.  You're unlikely to find such a system in the USA -- and in fact I'm kind of amazed that UK homes commonly have such a layout.  USA systems typically have one to 3 or 4 zones in the house, and all zone valves are near the boiler.  A given zone will heat a few rooms with a single pipe loop, so you can't control on a by-room basis.

My impression is that this system is much more useful in a multi-office business space, as it allows centralized control of the existing valves in each office space.