WD Gold are hard drives for data centre applications, i.e. for business customers. They are louder and get hotter than the consumer grade hard drives (e.g. Black). I do not recommend using gold for private use.
I have only used WD Black up to now (> 5 years) and have never been disappointed.
The WD Black requires less power in operation and therefore stays cooler.
The difference is even greater in standby.
Black 0.8 W / Gold 5.9 W.