What do you think the ideal BOB (Bug Out Bag) bag is?

5031 Three Day Pass (36 Litre)	5016 Bugout Bag (55 Litre)
Technical pack with built-in hydration system compatibility. Cargo pocket with MOLLE panel. Features: padded non-slip shoulder straps, adjustable everything, waist strap, organizer compartment, and front zip compartment gives that extra features that everybody needs.	Carries like a travel bag, yet coverts to a backpack in seconds. The expandable main compartment has a large opening that allows packing and re-packing easily while on the go. Padded straps for comfort, with internal frame allows for stability during transit. Feature: 600 Denier Poly/Canvas, Stress point reinforced stitching, Padded tuck-away straps, Converts to backpack, organizer panel, Padded carry strap, Name tag panel, Luggage tag.
Dimensions: 15 x 8 x 20 in. Weight: 4.5	Dimensions: 21 x 9 x 13 in. (Unexpanded) Weight: 6.5

French Gas Mask Bag
The standard French gas mask bag can be bought (along with the mask itself, a filter, and some lenses) for around $20 USD at the local M&I Surplus. It has two external pockets that can fit a water bottle each. The internal pouch has a cloth divider that makes three extra pouches. The first two can fit a small bottle of butane lighter fluid each. The other one can hold a beer bottle (maybe). The one downside is that it is too small for a regular BOB, but it is light enough to be carried along with a different BOB.
Dimensions: ? Weight: ?

The link for these bags, and others, is http://www.bugoutgear.co.uk/bug_out_gear_packs.htm (It is a UK website)