nunya's dashboard

I own a Laptop Messenger and love it, but I'm pretty intrigued by the new Mullett. It looks like either would hold my 15" Macbook Pro in the medium size, and there are a couple cool new pockets, but what's the real difference? Looks to be about the same size, but might not be waterproof or have "heavy-duty stitching?" Is there a key ring tether? Seems like these would be items not to take out of the travel line, so I'm wondering if that info is just missing on the site.