Multi-monitor gaming is pretty pointless since most of your attention is focused on what's directly in front of you i.e in the middle. This is proven science. But you don't really need science for proof; notice how no one ever games with an even number of monitors? It's always an odd number of monitors. Why? Because there's always a monitor in the middle, where 95% of your attention will be.
Totally agree - I'd much rather have a 2650x1440 or a 2650x1080 monitor than 3x1080p monitors. Maybe just as expensive, but games would run more smoothly.