Mro,
I just went through the buying process on spotters as well. I have some distinct needs as concerns eye relief, so my options were definitely limited. That said, I looked through everything to try and find something that would work for me while researching. While that did not include Kowa, due to availability for me to look at, what I learned is that they are universally considered top drawer. The only drawbacks that folks mentioned to me were it's lack of tough armoring, and the relatively short eye relief (which is what put it out of consideration for me). Some folks wondered about their warranty...Swaro has a good reputation for taking care of their customers. Not that Kowa does not take care of folks, it's just an unknown.
On the Swaro side, well, they have a reputation for a reason. Just great stuff all around. Pricey, and some folks might say the Kowa is a bit better in some areas, but others disagreed. One thing about the Swaro, you will never have a problem getting out of it if you decide you don't need them any further. Resale is not an issue.
I checked out Leica and Zeiss as well, spent some time talking to their folks at DSC and NRA. Their stuff is very nice as well. But I think that Swaro is a the safest bet when you consider resale, their reputation goes before them, everyone wants one....quality is arguable between all these three with opinions coming from all angles. Viewing is subjective to a degree. One thing to further note is that they all look fine in bright lights....you separate the men from the boys at low light, but all of these are definitely 'grownups'.
All the previous brands, I feel, are top shelf. Vortex, while good, is not, in my experience, in the same class. Of course, it's not in the same price bracket either.
If you can afford it, I would check the Kowa if you can and make your decision from there. If you want to consider resale 'insurance' in the future, Swaro is very strong in this respect, and are setup very well for hunting.
HTH!
