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Welp I recently purchased two Apple Cinema displays, one for home, one for work. They are fantastic, and I appreciate the 2560 x 1440 resolution. If you work on a lot of text documents or write a lot, the text is really, really smooth and crisp, including Word, Excel, and PDFs.

If it were me, I'd get the superior Cinema display, well worth it in my opinion.
 
Go with the Dells... cheaper and pretty good. IPS panels on Dell monitors are excellent.... I have 2x U2311H so I know.

Plus, they have the upper hand over Apple Cinema Displays since you can height adjust, tilt and swivel. Three extremely basic features you expect out of a good monitor.
 
I would go with the new ACD. It will work nicely with an Apple laptop if you end up going that route and to me it is a higher standard. Also, the two screens will be identical so switching back and forth will be smoother
 
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