Dell UltraSharp U2713H vs U2711
As regards the most essential, which is of course performance (colors, clarity, etc) I would say, as my personal opinion, having used both monitors for some time, that if you already use the U2711, you do not really need to change it, but if you finally change it, you won’t be disappointed. Of course the same is true regarding the users of U2713H, you do not need to change it for U2711. This means, whatever of these monitors you have, you should be just happy — even happier with the newer at least from the aspect of health, since the U2713H permits even more decrease of brightness levels without losing sharpness, thus protecting further your eyes.
Yet I must admit that personally I prefer the aggressive coating of the U2711, much more effective when the monitor is near sources of light, especially near windows. U2713H near Windows is problematic (better not have a window behind you, especially when the day is shiny), without, as I said, becoming useless like Apple glossy monitors.
It is said that the U2711 and U2713H are more useful to colour enthusiasts, photographers and designers because of their wide gamut support (a colour palette of 1.07 billion colours, in a relevant end to end 10-bit workflow), but I believe that even ‘ordinary’ people can understand and enjoy this quality, even if they don’t ‘need’ it.