Personaly I really like the
Personaly I really like the Auto mode but you could always use it manually like any other system : set a temperature with the dial and choose the function, vents and fan speed.
If you press "auto" the system will simply decide the "best" way to maintain the set temperature : which vents, which fan speed, AC or not, recirc or not. In winter, it will not blow much until heat is available from the engine (I find my LE Eco is on the slow side with that... plus I have to set temperature a bit higher than desire, say 23C to feel 20C) then the fan speed will increase - sometimes to max - and decrease by itself to maintain the temp. If you hit any button (say defrost), auto disengage until you press auto again.
AC will engage even in lower temperature while heating - but never below freezing - as a dehumidifier. You can disengage this automatic function via "vehicule setup" on the touchscreen.
So basically I always leave it on Auto (except for the occasional defrost) and it does all it has to do to keep the cabin at the set temperature.