I rated Nickel a little better than Zeiss and so would probably go with a Nickel if money was no object and I wanted the best but in saying that I haven't seen any of the new Zeiss glass. I think that without question Zeiss are ahead of the other big names when it comes to glass but the other names offer advantages in terms of brand profile or back up if something goes wrong and the glass in them is certainly adequate for what we do with them so, as always, the choice will depend on exactly where your priorities lie.