At least 2 of the regulars in our group have gone from Swaro to Razors and when others buy new they go Razor.
I was surprised by how good the UHD 10x42 looked to my eyes when I first tried them. Shocked actually. I compared to an EL 10x42 and preferred the UHD. The UHD seemed brighter and I could see more detail. Samples of one though; both brand new units.
That was three years ago when I first looked through the UHD, but earlier this year I was talking to a somewhat well known industry guy and asked him what he thought about the UHD. In his opinion, he thought it was optically better than the EL. He sells both and the biggest gripe with the UHD is build quality.
I'm not really a Vortex fan, and use SLC 8x42 as my main binocs, but I still think that the UHD 10x42 are really nice. I don't know about the other formats like the 18x though.
I'd like to compare the UHD, Maven, and SIG sometime for fun. The A-K designs. I think that they are all Kamakura?
I have become a fan of image stabilized binocs. Got hooked with the 16x42 SIG and now use the 15x50 Canon.