Personaly! I think the old beast, 28-70, is one of the best zooms ever made and many would agree on that. Problem is: not very practical zoom-range.
Ive used the 24-70 a lot with the D3X, good lens but not one of my favourites, some samples show plenty of CA at 24 mil and I dont like the cheap desing of a helicod barrell.
Chris