Brown vs white coturnix

[Huntmaster]

My experience is this, I've had browns and whites. I have had nothing but aggressive behavior in the browns (jumbo)....hatched a batch of a&m whites and they are the calmest, mellowed out birds ever, I've NEVER had any fighting with my whites but the browns are ruthless!
Getting ready to order more hatching eggs are yes they WILL be the whites again and NEVER AGAIN THE BROWNS.
My quail are raised inside a spare bedroom in my home.

I have Jumbo Whites from 2 different sources and my Jumbo Browns are from 3, 2 being from same source as whites and all from JMF lines. Both my lines of whites are a little more aggressive/flighty than my browns, one line of my browns is about the same as my lesser aggressive whites. But like you said you had demon Jumbo Browns, I had same experience with 1 line of my Jumbo whites. I have since bred out some of that aggression with this demon line but still harder to work with. In my experience with Jumbo Coturnix Quail in general as that's all I have raised, can be nasty little buggers sometimes even if all precautions are taken.