In article Autolycus wrote:

[snip - comparison of Honeywell CM Zone Wireless system against hardwired
motorised valves]

Less sophisticated control, and it's more work wiring it all up, but
each item can be replaced if it fails by something functionally
identical from another maker, and it leaves £425 to spend on tools, or
sweets.

I'm inclined to agree there. I looked at the CM Zone option as a less
disruptive way of applying zones to our existing system but dismissed it as
an expensive approach with some practical drawbacks. If we were starting
from scratch I'd go for zones with motorised valves but I don't fancy the
disruption so I expect we'll settle for a relatively cheap and cheerful
addition of a CM927 to the existing system which has TRVs throughout but no
room stat.

--
Mike Clarke