Smart cool mist humidifiers actually work or make a difference?

Has anyone used a "smart" cool mist humidifier or any type of cool mist one and have you found it helps your baby sleep better? There are 2 types ultrasonic and evaporative, what has everyone heard about which is better? I live in the northeast, it's winter and very dry air. My pediatricians practice do not like humidifiers bc of mold. My 8 month old has had 3 ear infections since November and the ENT said cool mist humidifier is fine just clean it.