It's probably neck and neck. There is an extensive discussion over on the LCD thread on AnandTech
(the last couple dozen pages of the thread). The HP is better claibrated out-of-the-box and has better blacks than the Dell; however, the Dell has 12-bit internal processing. Both need real calibration if you plan to work with color sensitive applications (e.g., web site design, photo &/ video editing). The sRGB & color space issues are non-issues if you are using color-space aware software (including Firefox and PhotoShop). Just make sure you are in "standard mode" then use something like the i1.display.2 for accurate calibration.
I own a pair of the HP LP2475W monitors and couldn't be happier. If I were buying today, I'd make the same choice because of the "blacks" -- I'm photo editing, not gaming.
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