Only real difference I saw was the 10bit color processing. If you don't need AdobeRGB space, why not get the 2713HM?
It also only uses roughly half the power of the U2711, if that matters to you. Weighs a lot less too. U2711U2713HM
Really I don't care about the power consumption or weight. I would much rather have the best picture possible, hence why I would rather go for the U2711 but there are a concerning amount of complaints about the anti-glare coating marring the white picture.
The coating that's used on many monitors with larger LG IPS panels (I have an HP ZR30w at home and use U3011's at work) is definitely noticeable on a white screen. Whether or not it would be an issue for you is a matter of opinion though; panels with intermediate coatings and the colorspace that the above mentioned monitors provide are quite slim, and if it's not coming from Dell/HP, you risk a lower quality control process and possibly more headaches with RMAs.
Also, if you're gaming, looking into input lag is important. I picked the ZR30w over the U3011 for this reason, as the scalars on the larger monitors tend to add a frame of input lag or more. The TFT Central Review of the U2713HM
shows it at 22ms, where as the HP ZR2740w, lacking a scalar or OSD, is at 10ms. Not all Dell monitors have this extra input lag, but it's definitely something worth considering. The HPs are otherwise spectacular in color quality.