Just want to add... some people seem to have strong opinions against X-Brite, because of glare, I think? So you might want to see them both in different scenarios. And the "best display in the store" thing is kind of disturbing... If Sony's 12" or 13" notebook has a better display than any of their 20+" desktop LCDs, it says more about their inability to make desktop LCDs than the quality of their notebook. I don't think there's any way with the current state of technology that a low power LCD could be better than ones with more available electrical power. Same deal for Apple. I don't think the expectation that the brightness of the PB12" match an ACD is a reasonable one.
I'm actually using a Dell 2001FP again with my iBook today... the Dell is brighter, of course. I think it's angle viewing is better too (that OTOH is something that doesn't have so much, AFAIK, to do with power). But I dunno...the color is better on my notebook. I've calibrated the Dell twice now and I haven't been completely satisfied with it. Maybe I just have to keep trying. The second calibration was substantially better than the first, because the first time, I didn't bother to use the expert mode.
Anyway, my point is, you need to A/B the two screens in question in the same room, on the same table, under the same circumstances. And preferably to repeat that in several different lightings. It is really dangerous to judge them based on seeing them in two different stores.
Anyway, good luck. With all that rant being said, in the limited time I've interacted with them, I liked X-brite screens. But I haven't used them in detail. And this has been a major FAQ here recently, with attendant flame wars in every thread about the merits of X-brite.