I have used both 2 piece and union suits. First point to consider with the union suit is can you use the bathroom without having to take it all of the way off. The link you gave said that the suit has a FULL zip around situation going so you can “fully relive” yourself. I can’t really tell but it looks like the zipper only comes down to the front crotch area. All union suits I have had came equipped with a convenient flap in the back.
Second is the temperature. Even in zero weather I have found that while huffing and puffing through the snow I still get sweaty with just a thin shirt on. Layering is obviously very important and it is a little difficult to take off a thermal union suit in 3 feet of snow.
So I guess my conclusion would have to be. I really wish I could use a Union suit while hiking because they are Soooo comfortable. But in the interest of ease of use, layering etc I have converted to the 2 piece situation.
I have on occasion used the military sock / shirt tail suspenders to keep thermals tucked in and those heavy wool socks pulled up.
Cameron
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