Hi, first of all i'll make it clear i'm new to EDC bags so pretty clueless where to even start. What it's for. Mainly it will contain a change of clothes for both of my daughters aged 18 months & 3 & a half, so other than a change of clothes, a drink each, wipes, diaper for the youngest & hopefully a little room left for a couple of my things, small knife, flashlight, small first aid kit could be useful too. I'm looking at approx 20L size bags unless advised otherwise. What i like. Personally i think i prefer 2 strap rucksacks rather than just a single strap, mainly as much of the time i have my daughters with me, so when i'm walking i want the backpack staying in place & not swinging around. Must be durable, OK i'm not going mountaineering, but still i'd like it to be reasonably tuff. Price I'm happy in the $50-$100 range, unless you can recommend me something cheaper! On a side note i did have a quick look on the internet, are the Maxpedition type bags really much better than say backpacks made by outdoor sports companies such as North Face or Under Armour? All opinions welcome, also happy to hear about brands to avoid too. Thank you.