The ease of manually controlling the thermostat's temperature set-point, heating/cooling schedule, home/away and vacation features - when they are available - through the thermostat and mobile app.

Is it because the old twist-knob was a "4-wire" thermostat that cuts power completely while the new RLV3120A is a "2-wire" thermostat that doesn't? I'm an electrical engineer but this is my first time ...