Assuming you had the space for it and you could freely choose, what display arrangement would you rather go for?
What's your dream setup?
@fribbledom definitely single screen. split screen always breaks the immersion. 
@fribbledom anything in general.
Unless for multitasking like
Live streaming something when you got different screen dedicated just for chat.
I don't see the point of having separate screen for my stuff.
@ravenclaw
You mean for gaming?