The Dell u3011 is a wide gamut panel. That means in any non-color managed app (ie, pretty much everything except photoshop) any primary color, especially red, is going to be grossly oversaturated. Skin tones get excessively red/orange. You might be used to it, or even like it, but it really isn't displaying proper colors (unless you have it set to sRGB, or are actually using a color-managed workflow with adobeRGB.) The Auria is not wide gamut (at least the glossy version isn't - if the matte version really is using a u2711 panel, then I suppose it could be.)
So depending how you have your color settings, it might have less vibrancy compared to the Dell. But if you have both of them set up properly, they should be quite comparable.
If you like the Dell, I would just find a pair of 20" 1600x1200 monitors to flank it in portrait - they will match up perfectly.