1. Add a Spec-Ops knife pouch to the shoulder strap...
2. Add a set of mil spec hearing protectors to the strap D ring...
3. Add a solid fuel handwarmer to the external side pocket...
4. Stuff the large internal zipper pocket with a matched pair of Otterbox 1000's - one with a First Aid Kit, one with your PSK...
5. Stuff the remainder of the pouch with other essentials you deem appropriate...
I use the internal water bottle mesh pocket for sunscreen, insect repellant and personal meds. The pen pockets carry spare tools for my ToolLogic knife (to be reviewed seperately). The ID pocket carries, well, ID. The small zipper pouch behind that carries a spare bandana and some extra Sweet-n-Low for my coffee. The large pouch carries my MSR Ti mug with 20oz Nalgene bottle nested inside, a XL Siltarp poncho by Equinox, a spare smoke kit, TP, a flashlight or two, and a Batuca battery case. The "under the flap" pocket hides an ammo wallet, while the zipper pocket in front of it stashes a few extra bills.
So far, the Timbuk2 Metro has been a WONDERFUL addition to my field and EDC gear. It carries everything I routinely need and still has room to spare for the odds-n-ends that one finds useful.
The bag has held up nicely under EDC use, banging and sliding around the floor of my truck, and a hard trip to PWYP.
I cannot rate a product higher than this...
M