I edc a get-home-bag instead of a B.O.B., and chose to go with a Maxpedition (the versipack) for its versatility as well as its durability. I've seen too many cheaper pieces of kit fall apart under what I would consider regular use. I chose the GHB route as I think the chances of me needing to evac my family on foot is very slim. Looking at the emergency situations I've been through - evac due to chemical spill, extended power outage - chances are I will either be hunkering down and home or evac'ing in the family car. Therefore my preps are not really foot mobile, but will serve us well at home and can quickly tossed in the car.
I guess the point I'm trying to get at is if the SHTF so hard that you need to ship out on foot, the look/colour/molle of your carry bag is going to be the least of your worries. The current situation in Port-au-Prince is the perfect example of this, as Cpl Punishment pointed out.