I am not a fixed blade person but here is what I would choose. I think that they are 2 completley different animals. the ESEE seems like the more down to earth knife to me. the steel will be easier to sharpen, and it is cheaper. however, the ZT looks really nice, has amazing steel, has that wonderful recurve, and would be great for general use. besides, it is in the price range.
as far as warrantys go, I think that kershaw will replace pretty much anything, no questions asked, but they don't spell it out. ESEE spells it out with no reservations.
I think I would go with the ESEE. I have always been a huge fan of kershaw and ZT, and they make up my entire collection, but i really never have understood the 0100 as anything but eye candy. the esee has taken a lot of hits and has survived, will be easier to resharpen, and is o so moddable.