I would add Tado and also honeywell to the list. Also make sure whatever you choose get one that can can modulated the boiler properly and has weather compensation for intelligent smart use rather than just an app based on/off system.
Also Hive would be bottom of my list as it’s pretty dumb in functionality.
I have had nest and now Tado in the new house. Some features are now subscription based in tado but can packs that have the full features included.
I liked the motion sensor that nest has and miss that in the tado. Tado is also relies on phone location to get the best of it.
Tado runs by boiler properly though that the app shows how hard it’s working the boiler when it’s triggered.
Start with boiler choice then look at the smart thermostat.