I've been programming for over three decades, and I still use monitors in the conventional landscape orientation, and I know of only one additional colleague who has taken to the portrait orientation. read more
Personally I run the IDE on a virtual machine on the horizontal screen (only one virtual monitor, two give more headaches IMHO) and I show the code I need to consult from GIT on the vertical monitor using the browser. Or I use other net services (like stackoverflow or google) on the vertical monitor. read more