I would say from the pictures, the ceramic case on the V2 appears to be "cleaner", noticeably the Top Gun engraving on the side of the case looks crisp and sharp. The dial may be better too, the markers at 12, 3, 6 and 9 seem to be much nicer, and from looking at all the dealer pictures, straight and aligned too.....
I really like the fact that the V2 movement has a proper spacer ring and is screwed down, the other IWC's have just that retainer spring, which to me looks weak and poor in terms of dial and movement security........
http://www.kingwatches.net/IWC-158.htm
Cheers!