Going for the 1920 x 1080 resolution of the 2690 to the 2560 x 1440 of the 271 takes a bit of adjustment...figuratively. I'll be interested to hear your experiences.
It arrived today - installed in about 5 minutes and communications back up and running. I love plug n' pray when it works

Its a hefty increase in resolution over the 2690 WUXi and my immediate impression is that its greatly appreciated. I need to make some prints though and spend a bit of time doing some heavy lifting image processing to really see how it stacks up - but I expect it to be a nice upgrade.
One immediate benefit is the library module in LR. Extra pixels there is VERY nice indeed.
Sad, that I had to confine the excellent 2690 WUXi to oblivion though - I might hold that against Apple for a while yet...

Edit - One other bonus of the new 27" NEC is that it also has 3 x USB ports on it as a hub. I had run out on my mac pro so this was an appreciated feature.