I have both an HP LP2475w (24" 1920x1200, IPS) and a 27" 2560x1440 monitor--the same resolution as mentioned here. (I didn't want to deal with potential dead pixels and scaling issues, so I forked over the $700 for the Asus PB278Q instead of buying the off-brand.)
Honestly, I hate using my HP now. It's a great monitor, but the 2560x1440 resolution on the Asus is amazing. Side by side, the Asus knocks the HP out of the park.
TLDR: It is not worth the downgrade in screen size and resolution just to get a 16x10 aspect ratio. You will never regret going for the 2560x1440 monitor instead.
It's a pain to cart around, but I love my 10-year-old 2048x1536 CRT, and am alternately amused and saddened that modern displays still have a smaller smallest dimension.
New technologies are usually better in some aspects in worse in others. Like LCD was a lot better for the thickness factor, but it took ages to make them the same quality as CRT and for the same reasonable price.
Now we're seeing this with OLED displays, too. Much better contrasts, and even having some special properties like being bendable, but cost more than regular LCD's or even IPS LCD's.
I had one of those at home. I took the hit on resolution and color to go LCD because the LCD's at work didn't make me feel as tired as the high-res CRT at home did.
I had the opposite; for a long time LCDs gave me headaches, I think because they were all 60Hz. (Recently I've bought a laptop with a 120Hz display, which doesn't give me headaches).
I have a 28" and a 24" both running 1920x1200 so that wouldn't be an upgrade. I think I bought almost the last monitors running at that resolution! I'd be happy replacing the 24" with something larger but it looks like the 27" 16:9 will actually be less vertical space.
My monitors are CCFL so they use a lot of power hence the desire to replace them eventually.
16:9 are physically smaller and use less material yet able to maintain the same screen size specification as a 16:10 monitor. Hence such difference is often missed/ignored by the ordinary customer and hence manufacturers are able to get away with this. In other words, 16:9 monitors == higher profit margins
The way I understand it, these panels are all basically cut from one continuous sheet in the factory, so it's difficult to re-tool a line to produce "taller" panels.
It's a calibrated IPS monitor, 24" 1920x1200 (i.e. 16:10).
I have one and it's great.