Both binos have very similar specs, with the Zeiss having a slightly wider
Neither were "sharp to the edge" when focussed on a distant object, so if you focussed in the centre and then move them to look at the same object nearer the edge of the field it became a bit out of focus. However, and this is something I have never seen explained in astro-reviews, they both have obviously been designed for birding/nature views more than astronomy, because when you focussed on a distant object in the centre they were in focus almost right to the edge on closer objects as well- ie: nearby bushes etc. were also in focus due to the designed "distortion" or curvature of the field. Thus that bird that popped up nearby while you were focused on the distant eagle was also in focus. If you then panned to the nearby intruder you had to reset the focus in the centre, but the panning wasn't necessary because you could check it out clearly by moving your eye, not the bino. A fascinating effect that I haven't noticed as strongly in "betas" like my Vanguards. (I believe that the technical term for this is "pincushion distortion" which was first developed by Zeiss, and makes the field take something of the shape of a "pincushion", in order to correct the "rolling ball" or "globe" effect caused by panning with an instrument that is designed to be free of distortion. However, that is enough technical stuff...) This of course means that when using them for wide-field astro viewing the stars at the edge are distorted, but there is a "sweet spot" of around 70-80% of the field where stars are sharp, before the built-in "pincushion" distortion takes effect. (For astro use, the Swaros seemed to have a slightly bigger sweet spot than the Zeiss.) I hope this makes sense!
In contrast, I suspect my Fuji 10x50's were designed more for distant/astro viewing. They have less built-in pin-cushion distortion and therefore have a bigger "sweet spot" than either of these two alphas when viewing star fields. However, in day-time viewing their individual focus in particular (not to mention their weight for carrying around!) and inability to focus close-up tells against them for nature viewing.
Bottom line. I am still very happy with my Fuji's for astro viewing (where I think they edge both the alphas), but if I had a very deep pocket and wanted the best for general viewing I would be very tempted by either the Swaros or the Zeiss. My preference is the Swaros: they simply felt better in the hand and gave a more pleasing view to me (very subjective of course!): and their colour rendering was nicer to me (plus they are about 20% cheaper if I were to purchase locally!).
However, I emphasise that this is my subjective view, and it is a bit like purchasing a fancy car: say a Mercedes vs a BMW. Both have very committed aficionados who will argue against the other!
Sadly, I had to hand both back to their owners: and the accounts department will not sanction my own purchasing of them. Definitely a "first world" problem though!
Happy viewing folks,