i don't think perfection is possible, because of the infinite variety. I don't mind a couple of pockets in a backpack (maybe one small one and one medium sized one), but I hate it when there are a ton of little slots for things to slide into that were designed with specific objects in mind but don't really work for any of them because I'm not using the same power adapter they used to design it, or because my cell phone is huge, or because i have too many keys...

what I would like: easy to clip on and off so that I can take it/them inside. flush with the top of the rack so that I can bungee something down there if need a little extra space (like my cooler), laptop section with real crush-resistant padding (not just a little soft foam), space for a folded pair of pants and shirt, space for a lunchbox, and a way to cover the rack hooks so they don't dig into my back. flames made out of reflective material would be a nice bonus, as would protective rain covers that also had reflective material on them. Maybe a way for a cable lock to go through the zippers and through the frame of the bike so I wouldn't have to carry them in on a 2-minute stop to get a sandwich or something. Oh, and if they could pedal for me when I get tired, that would be nice...