I got a 23" 2 weeks ago with a mac mini and applecare. It doesnt have any color problem, and the display itself is amazing. I do have one problem with it, there is a backlight problem (on of the lights in the monitor is dimmer) resulting in a darker line across the top of the screen. I called them and offered to replace it asap. People at apple care are realy friendly.
I will exchange it in january since I'm too busy to send it atm, and apple tech said it was no problem, I had 3 years with apple care.
So if they release a new one in jan. when I return my model I might get the new model.
But I dont realy care, latest revision of this monitor is amazing, just make sure you dont buy it in a store (as usualy they have been sitting there for months - so they have the old revisions problems).
The only thing is, when you get used to 23" after a week or 2, it starts to feel small... Next monitor I buy will be the 30"
Anyway, I realy love my monitor, and I realy woudnt see myself having a plastic dell instead. Alluminium make it feel as a much better quality monitor.
Edit: Apple care with monitor on a mac mini cost almost 200$ can$ less. So if your thinking about getting a mini, you can look at it like your saving on applecare (since the smaller mini is like 550$ student price, it drops it to like 350-400$ and you get a 3 year monitor protection
).