How does the Cafe Bag travel with the Aeronaut? I'd still be inclined to choose Ballistic Nylon, or a closed design Cordura bag for the rainy conditions he describes. I still love my original design Buzz, but that's with a 12" laptop, smaller carrying load, and Urutek splash-proof zippers (and a water bottle pocket!), and it wouldn't work for him with the MacBook and larger load; the Buzz design doesn't take to "overpacking" and it's basically great for a more minimalist philosophy of carry.
this note about the rapidly diminishing availability of the Swift, which you might want to consider in place of the Lux, since there are more color options (if they don't all sell out), and some newer revisions in the interior pocket design (plus you get a black/white stuff sack, which can be useful even if you don't knit ;-).