Nice middle layer
I wanted a new vest as my current Marmot vest (model unknown, Large, orange, 2-3 years old, 650 down fill) is slightly too big. Turns out that the Zeus is a very different vest, much lighter, thinner (800 down). Given that my current jacket (large) is too big for me I went for a medium Zeus but this is too small (btw I'm 5'11 200lbs)... so the sizes between the styles appear to be quite different.
Now that I've done my homework a bit better I realize that I am comparing apples to oranges and that the Zeus was made for a different purpose. Knowing that now, I'd rate the Zeus a very nice vest that's great for layering or as your sole jacket on somewhat 'nippy' fall days.