After having both side by side, I would never trade a pair of Viper HD's for the BX-4 Leupys. Image quality of the Leupolds is next-level. The field of view is barely narrower than the Vipers. The image the Leupolds deliver is so good, that I didn't really notice the narrower field of view that much. It bothered me on the C1's (along with other annoyances) but the Leupolds are just darn good instruments. I forgot how much I liked the open bridge design. I loved it with my original Mojave's years ago, and again with my Sightron Blue Sky II 8x32's. For a hunting binocular, an open hinge design is very useful because you often have gloves and need something to hang on to.
After just one evening in the deer blind, I have no doubt I made the right choice today.
This particular deer blind I sat in tonight may as well be my "optics lab." I have used it to test about a dozen pairs of binoculars side-by-side now, because I have so many targets to choose from, with so many textures, colors and distances. Everything from fine grass and barbed wire fencing, to big fat oak leaves and red berries and radio towers in the distance. And on an evening like tonight, with clear dry winter light, the resolution was on full display.
I've tested Conquest HD's, Swaro SLC's, Nikon M7's and HG's, Maven C1's, Cabelas Outfitter HD's, Bushnell Legends, Legend M's, Leupold BX-3's, Mojaves, Alpens, Opticrons and others I have since forgotten from that same blind. I have nice 2x4 windowsills to rest them on, so I don't need a tripod. It's a great real-world testing ground.
Aside from the extremely high resolution (as good as anything I've owned, including Conquest HD's and SLC's), the light gathering is what really impressed me. Easily as bright as any 10x42 I've ever looked through. I could see barbs on a barbed-wire fence a measured 200 yards away, a full 30 minutes after sunset. With my naked eyes, I couldn't even see the fenceposts. That's some serious light gathering for a 10x42.
I was looking at the BX-4's side by side with two pairs of Monarch 7's today in the store. The 10x42 BX-4's were much brighter than the 10x42 M7's, and to my surprise, were brighter even than the 8x42 M7's. That's when I knew I had to give them a try in the real world. And the delivered.