I’ll have a go at it.
I haven’t had all of those together at one time, but I’ve had most of them side-by-side with one another.
I had the Genesis 8x33 side by side with Swaro 8x32SV, Zeiss SF 8x32 , Leica Ultravid 8x32 and NL.
I’ve also had the Genesis 8.5x44 side by side with Swaro SV 8.5x42 , Leica Noctivid 8x42 the NL 8x42 and an old Swift Audubon ED 8.5x44.
My overall summation is the big three Zeiss, Swarovski and Leica are all as good as it gets. I’m not going to go into how each one compares, I’m sure there are numerous discussions on each here on BF. In comparing all these , as usual it comes down to , you pay for what you get. That being said I’ve come to a conclusion over the last few years that imo the $1000 (upper mid grade) price range is kind of a sweet spot when it comes to what you get for the money when comparing them to the best of the best, and the mid level options that range about half that price ($500 range). We seem to get most of the attributes of the best , excellent high quality optics and build. From there improvements are very incremental , and some people for multiple reasons my not see the difference of the best of the best , but most do, once you know what your looking at. The top four (I added Nikon) do have something that I find lacking in the upper mid level options. I guess we get spoiled after using the alphas , once you look through the best you never want to go back.
The Genesis falls behind in snap, crackle pop in the image behind the top four, and imo is closer to the old Swift than to the top alphas. The Kowa is still overall superior to the Swift, but on axis image detail and sharpness is right on par with the Genesis.
Paul