If color accuracy is important, know if you need narrow (sRGB) or wide (aRGB) monitor....and get a Spyder or Munki package to calibrate it. That goes for any brand of screen.
In fairness to the expensive ATD, it much more than just a good sRGB IPS screen. It is also a charging station for Mac laptops, provides a thunderbolt docking station for Macs, contains a USB 2 hub, contains a FW port, contains a GB ethernet port, integrated camera, and integrated speakers.
Yep, an ATD is not inexpensive. But compare it to the cost of a Dell U2711 plus a Delkin thunderbolt dock ($399). Those two will still not provide all the functions of the ATD.
Best prices I have found for ATD are $829 at Apple for refurbed with full warranty and $929 at B&H for a new one.