Justin I have been wearing the Arma hoody quite a bit. I have a couple Halstead fleece and Sitka Heavy weight Fleece. I really like the Arma Hoodie but it is cut way different than the Halstead or the Sitka Heavyweight. The cut on the Arama is wider in the sleeves. The fabric is quite stretchy just like the Halstead but the cut of the sleeves is much roomier so the stretch does not really play a factor for me anyway. The Arma feels thicker than the halstead but it does not block the wind any better and seems to dry slightly slower than the Halstead. I do not own the Klamath because I dislike the hood zipping all the way to my nose so I have no experience with it. The hood on the Arma only adjusts vertically and the hood is slightly large so it is slightly in your peripheral vision. I wish the hood had a rear adjustment on the Arma as that would have solved this issue. The Arma feels much heavier in general over the Halstead but it has a full zipper, two hand pockets with zippers and a hood with adjustment cord so it really is a whole different animal. I personally don't think that the Arma Hoody is any warmer than the Halstead outside of insulating your head with the hood. I like them both equally for differn't reasons. Hope this helps. I can post some pictures of me wearing the Arma Hoody so you can see the fit on the arms or if you have any other questions just let me know. Just for reference I wear an Large in the Halstead, Xl in the Sitka Heavyweight hoody and the Arma Hoody in XL. I could probably fit in the Large Arma Hoody but I am glad I went XL . I am 6ft3 220lbs and Average build. My chest is larger than my gut....... for now anyway. HA HA!