1920x1200 monitors are way less common, and more expensive. They're usually better for everything but gaming. When it comes to web browsing, you'll notice you have to scroll down a bit less, or have room for more toolbars. There is no quality difference based only on Resolution, it all comes down to other specifications.
2560x1440 has more pixels than a 1080p screen, but if its colors, backlighting, view angles and refresh rate is bad, most people would prefer the 1080p one. Quality.. not quantity.
16:9 ratios are better in nearly all games, unfortunately. I KNOW the extra vertical pixels seem amazing, but they do more harm than they do you good. I'd stop gaming at 1920x1200.
I really wish it worked differently, but in most cases it doesn't.
Gaming at 16:10 is losing you horizontal view space, and not giving you any vertical advantage
Here is an example of what you lose by using a different Aspect Ratio than 16:9 in World of Warcraft.
Here are the pictures used. I had to scale the higher res pictures down in height to the correct height so they'd match in that previous picture, but it's still accurate.16:9 1280x72016:10 1280x8004:3 1280x9605:4 1280x1024
Pay very close attention to the very top of the screen, and the very bottom. All throughout the pictures that never changes.
If I were you, I would just deal with some small black bars at the top and bottom in favor of the bigger viewport and enjoy the extra pixels when doing other things. They ARE useful, just not for gaming :\Edited by Shadow11377 - 8/26/12 at 2:27pm