We have both 1080 and 1200 in the house. I use 1200 H-IPS screen (my center monitor) and my wife uses 1080 cPVA screen. Once I'm using one or the other for a few minutes, it seems right. We have 10 monitors in the house -- Samsung, Dell, HP. We've had ASUS LED and ACER cheap gaming monitors -- which we gave away.
The extra pixels of the 1200 come in handy for non-gaming applications (as others have mentioned).
Also, the bigger the monitor and the closer one sits, the higher the resolution needs to be. Our 27" 1080 monitor looks great for size. But, the pixels tend to be visible up close -- its better at a distance which is how we use it. Overall, I like it though -- 27" beats 24" for gaming. Still, if exceeding 24", one might want to go 1200 -- a matter of personal taste.
Mainly, get a good quality monitor. We DO see the difference between our normal-quality monitors and our higher end monitors -- in color mostly -- but also in black level and off-axis viewing.
Most monitors come with poorly adjusted colors. One can download free test charts one can use to "eyeball" the colors into better adjustment.
For what its worth. Just personal taste in monitors. Each person sees things differently.
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