The high end dell monitors are great for photography work with their AdobeRGB color-space, I have the u3011 myself. And it works fine for gaming, despite most reviews harpering on input lag, etc, which they do, compared to dedicated "gaming monitors". The pixel display rate is fine, even though a 120Hz monitor will be smoother for fast motions. The problem with pure gaming monitors is that they are usually anemic in many other areas, among those, especially color fidelity.
What it comes down to is what you must have in a monitor. For me it was ability to work at high res with great color. Gaming second, even though gaming takes a whole lot more when time is considered.
Guess you already looked at the Anandtech review http://www.anandtech.com/show/2922