I really have nothing to add. I have been using a Chrome medium for commuting for a decade. There is a little rust at the buckle from my sweat, but it has held up really well. Pretty much the same as you Timbuk2.
I use a Chrome large for an over-night/weekend bag. That one doesn’t get sweaty and probably will last me for life. Both the medium and large fit my 15.6 Asus if need be. That is my only requirement. If that fits, pretty much every thing else does. Although I have gotten creative using the bag and the stretchy packing film to attach large items for my commute.