IMO I think you're spot on. I'm waiting for my Wald 137 (the littler one) to show up. Throw your lunch, coffee thermos, digital camera with a pelican case, cell phone, wallet, pocket change, receipts.... and the list goes on. With the smaller one you can't over load it unless you go out of your way to. Some of the larges ones are too heavy when they're empty! But as for the 137, or 139. Or most of any Wald products, you really can't go wrong.
Wald--keeping it real and not changing a product since 1905
my $.02