Evohome was reasonably straightforward, just making sure you wire the relay box correctly and then it’s just binding everything, the radiator TRV controllers were a doddle to fit and bind. Altho I had the support of the shop I bought the kit from when, a few months later, I had a comms issues between controller and relay box, altho I probably could have worked it out for myself from the manual, I was just being lazy.
which system? difficult one really and I expect everyone will recommend theirs without having much or any experience of other systems or your requirements. If you want to control every radiator individually then it’s Evohome and maybe Tado maybe Natatmo(?) now also. I’m not a fan of the learning systems, would rather just have location, heating turn off when the last person leaves the house and turn on when the first person home is a certain distance away. I considered Tado, but there were questions I had on the new to market radiator TRV controllers, which I couldn’t find answers to, so decided to go with the well established Evohome. I also felt that investing in Honeywell kit was a safer bet than some recent start up company. I would only recommend Evohome if you want to control every radiator individually, other aspects of it are a bit clunky and ugly (def designed by engineers rather than graphic designers/marketing Dept). Honeywell Lyric might be worth looking at, which is more in line with Nest, Hive etc. cosmetically and functionally