Something else I just remembered since I haven't had to calibrate two displays connected to the same video card in that if you are going the video card RGB gain WB adjust route through software with the MBP, you might end up changing the NEC's WB because on the last system I had (G5 iMac OS X Tiger) only one RGB gain WB curve can occupy the video card.
Since the NEC doesn't establish WB through the video card and uses its internal hardware LUTs, you may have to figure out how to make the NEC loaded profile the main (dominant) display profile and not the MBP's profile.
You may not run into this but thought I'ld just mention it as FYI for others.
Tim, to be clear, in my case, I am talking about two discrete systems: a MBP with its Retina Screen and a Mac Mini with the NEC monitor.
Of course, at some point, I will probably want/need to use the MBP with the NEC monitor, which I guess would lead to another question that I should probably address in a different post.
Comparing the calibrated MBP/Retina view with that of the calibrated Mini/NEC, the Retina view is a bit cooler, with possibly a slight purplish tint (although I have always thought the calibrated NEC had a very slight greenish tint).