I think I know what you mean by the Nikon zoom, but if you had had the chance to have lived with it for a while - and I use a Swaro zoom regularly, too - I think that the Nikon is a little beauty (the Swaro is so large in comparison) that might well have won you over. Its mechanical merits are, in themselves, worthy of the highest praise: unlike others, no use of plastics, for a start; it looks and feels as if it's made with watch-like precision - the smoothness and solidity are unparalleled.
If it falls down, it's on its comparatively somewhat narrower wide field of view - but, I just cannot agree with you (as Tim and Leif would not, I see) that it is less contrasty or less sharp; and let's be honest, no zoom (even the Zeiss) is sufficiently wide-angled to obviate the usefulness of a genuine fixed wide angle (after all, would we put up with zoom binoculars with a narrow FOV?). The Nikon zoom has much in its favour - not least, the image it crates is unusually faithful and true to the original. And, when a truly wide view is needed, the Nikon 30x wide gains high praise from all reviewers.
As for weight - well, it's a very well-constructed scope and it's on a par with both Leica and Zeiss, isn't it? Yet... it's no longer than the Swaro 65! If the Nikon has a weakness, I would point to its rather high geared focusing, which, speedy as it is, needs care at the highest magnification - which, by the way, is a very useful 75x (okay - this needs good light to give of its very best, but when the light is fine, this is very useful indeed).