Interior velcro, not exterior. That's what they use on the International Space Station to keep things in place -- the walls have patches of the loop side all over the place, and any object that might drift off has a patch of the hook side on it.. Seems like a good system to me.

To be honest, I don't know what the volume of my old pack was. It was a gift when I was a teenager. I ran into a site that listed "normal" backpacking pack sizes as 40-60 liters, so I listed that number. I do have a fair amount of experience -- I've backpacked in the mountains in New Mexico, the Grand Tetons, Japan, and many other places before -- so this is nothing new to me. However, my old pack fell apart on my last trip, so I have to get a new one.