I would say that a sizable percentage of serious iRacers use triple-monitor setups to get the peripheral vision that is otherwise lacking. I'd like to do that someday too, when free monitors fall out of the sky and land on my desk.
Yeah, three monitors seems like a better setup than TrackIR. Easier to glance around than turn your whole head. Oculus Rift would be a good option too if it doesn't make you dizzy.