I have both the EB Expedition and mid-weight baselayers and love them both. As mentioned the expedition weight layers are way too heavy to hike in, but great for very cold or less strenuous activities.
I found that in cool weather I could realistically hike in the mid-weight layers, which are simply a thinner version of the products reviewed here. In the summer I carry them as part of the sleep system. Men's XL mid-weight top weighs 6.7 oz, size L bottom weighs 5.6 oz. They are the lightest mid-weights I could find.
Beauty is both expedition and mid-weights are all on 1/2 off sale right now at
http://www.eddiebauer.com/EB/Mens-Outerwear/First-Ascent/index.cat
Have fun!