Glenn; Those "drawbacks" you mention, can also be pluses! Handle too hot to hold- then you know the liquid will be too hot too, the metal transfers heat quickly, which means it will warm up again quickly beside the fire, no top- easy to see if it's your cafe au lait or buddy's thick as tar reboiled sludge, as for volume
mine are 10 oz, just like my mugs at home, and that funny shape means no tight corners to scrub stew out of, and they seem to fit wonderfully in tight little, weird corners of your pack, plus what else is there where you can fit an entire cookset for 4 (4 cups, 4 spoons, and condiments) in a one litre pot?