Just keep in mind you may or may not get a panel that will suit your purposes... Dell uses two types of panel in this model. S-IPS and S-PVA. Both have strong points and weak points. Type "Dell LCD lottery" into google and do your research before jumping on the dell bandwagon. If you want a guarenteed S-IPS, get the ACD. If you want to play the lottery, save some money, and possibly play an exchange game, go with the Dell...
That being said, I got the dell, ended up with an S-IPS panel, which is generally considered the better of the two, and I'm not entirely happy with it. With a grey, or mid-range darker background (not black), I can see waves (forget the technical term people use), and its really annoying. Its still new, so I'm going to spend some more time looking into if this is an issue with the one I got, or one with the S-IPS panels in general, before I play the exchange game... Other than that, I'm very pleased with everything else about it.
And, with all the above, you never mentioned what your usage will be, so either the S-IPS or the S-PVA might be just fine for you... Research off this forum. Very little seem to understand the dell lottery thing.