Damn, this information is making me more and more confused.
I think I'm going to rule out the medium travel bag because of the 18" length, a 20" long duffle like the medium makes things like tossing in a folded over sportcoat easier. Shame because I like the overall design of the travel much more. My current weekender is identical dimensions to the medium duffle and has worked perfectly, just looking for a nicer bag.
That leaves me with colour. I thought I had settled on navy, but the above comments about thinness have me concerned. Does it feel significantly cheaper in quality? How well does the otter green look in a more formal setting, or is it on the rustic side?