Nest / Climote / Netamo / Heatmiser - mystery...

All

Bit of a newie to this. I'm interested in a smart thermometer for the house.
I've a standard 3 bed semi, 1,000sq ft. I've got an efficient gas boiler and thermostatic valves on the rads. The gas boiler has a programmable timer and separate zones for heating and water. Typically in winter we have the heating on for an hour in the morning and again for 2 hours in the evening. For autumn and spring the evening tends to be just for an hour. Again water is on for an hour in morning and evening. Typically we have 2 pressure pumped (2 bar) showers in the morning and a bath every 2nd night for the kids. Plus the evening pots and pans. Also have a wood stove (not a boiler)

From looking around I see lots of opinions and options on the technology.
Nest
Climote
Heatmiser
Netamo

I’m not really interested in a bundle deal, just buying outright and switching providers as needed.

I’ve a couple of questions
1) What’s the expert view on the ‘best’ thermometer? I’m leaning towards Nest, but really because of Google backing and I’ll likely get a Nest cam and Google Home device too in the future.

2) How do they actually work? Do I’ve the heating ‘on’ fulltime and let the thermometer control when the heating comes on? Can I override it a trigger a boost, especially to the bedrooms in the winter evenings when kids are asleep but the fire is lit downstairs.

(Couldn't see an recent threads so starting a fresh)