I've set my own schedule with nest, and it still reset it to its own weird (and far too warm) schedule

You need to turn off learning mode, otherwise it eventually overrides your schedule.

Personally I think it's significantly better than what was common ( in the UK ) before, but the tech is dime a dozen, and new houses should probably come with underfloor, and control per room, though most still don't.

I had Hive before and prefer that; being able to boost the heating to a certain temperature for 30/60/120 mins is a common use case for me that Nest doesn't do.