Cato:
I wonder, is there or should there be a difference in backpacks for survival gear? You used the word "innocent" and it got me thinking. I've got two packs, one at home, and one at work. My work pack is OD, the one at home is Woodland. I didn't get these packs specifically for their current use, I just happened to them when I decided to pull together stuff that I might need. My work pack remains stored in my office closet, where it will remain until it is needed or until I leave for another position.
I gather that the "innocence" of the bag might be of some value pre-emergency, but I question its value during or after an emergency. One might not want to alarm others with one's preparedness, and one might also not want to look overtly militaristic or overzealous or something, I suppose. However, unless one is carrying around this kit, others would be unaware of its existence, let alone whether it is "innocent" looking or not. And certainly, during an emergency, it really doesn't matter what others think; it's about survival.
May I suggest that the key criteria are function, space, and comfort. Looks are a distant fourth.
atty_guy