I have the Kelvin jacket and Kelvin vest in the Mothwing Mountain Mimicry pattern and they are great -- very light, form fitting, comfortable and WARM. In order of personal preference of the camo patterns Sitka has used, I like ASAT the best, but I do not believe the Kelvin series was never offered in that pattern. Next, the Mountain Mimicry and the Mossy Oak Treestand are about equal in my view and work very well. The Optifade Open Country is close behind the MM and the Treestand and probably is about the same to the animals. However, I think the Optifade Forest is simply too much of a dark blob beyond 20 yards for most conditions that I will ever hunt in, and it appears that much of the new Sitka clothing is only being offered in the Forest camo, unless I am looking in the wrong places. If I were sitting in a patch of cedar trees or other dark growth while hunting deer in the early season or hunting turkeys in the spring, the Forest camo would work very well. But so would solid green. For most of my hunting, especially the late season deer hunting where I need cold weather clothing, Forest is not a pattern I would generally wear, and certainly would not buy at the prices charged for Sitka gear.
As a big fan of Sitka gear who owns thousands of dollars of the stuff, I think Sitka has done great things with much of its new clothing but has gone in the wrong direction with its camo offerings. I have read all about how animals are supposed to see and how the Optifade patterns were designed to deal with the animals' seeing ability, but if I can see a big dark blob standing out in the surrounding terrain, then I am confident a deer can too. ASAT, Predator, and Kuiu all use the big patterns that really break up a human outline and are difficult to identify, even by other humans. I have been busted by turkeys at long distances (70 yards) when I was in ASAT camo sitting in the middle of almost solid green growth, but unlike most game animals, turkeys see color. That was one of the few situations where the Forest camo would have been perfect, but the Spring weather was way too warm for any of the insulated clothing that I believe Sitka gear is making exclusively in Forest.
I am certainly willing to be corrected if I am wrong about the colors and patterns being offered in Sitka's cold weather clothing because the clothing itself is great stuff and no one else is currently selling alternative clothing that occupies the same market niche. I bought tons of Sitka gear because I really like it, and I would like to be able to have an outer appearance on the newer models of cold weather clothing that would work for me so I could justify spending the money on outerwear that is otherwise undoubtedly very well designed and made.
Allan