Agree with Matthew Langley. Also, the RGBs on the back of the monitor certainly do serve a purpose: If your system is against a wall/ in a corner, they light up the wall, making nice ambient lighting. If your desk is visible from the back, then you can see the lights directly, of course. Either way, they do work and are nice to have.
This monitor's looks are much more appealing to the over-25 crowd, and it will almost certainly have better QC than the Acer (funny how everyone neglects to mention all the issues and the RECALL). Hasn't anyone noticed the seemingly endless supply of refurbs available? Dell's customer support and exchange policy destroys the competition as well. Finally, this monitor can be found for $999 regularly. The Acer/Asus models have nothing on the AW.
Your link to Dell is wrong, this monitor is not $399.99