I like the ESEE knives a bunch, but my roommate owns a Campanion, and I have to tell you that it is one heck of a knife. For me personally, I lean towards the ESEE almost entirely because I like the way they do business. Thats not to say that Kabar is a bad company though! In fact, I kind of flip flop in my head which one I would actually choose. Anyway, they are both very good knives and I genuinely feel you can't go wrong with either.
With that being said, take the advice of carrying two knives into the field with you. I would say that even something like your basic SAK is useful in the field for any number of tasks that are possible, but more awkward, with a bigger knife. I personally have a Kit Carson designed CRKT bird and trout knife (that is no longer made) that has been a companion with me in the field for a long time now, and it has paid for itself many, many times over.