Don't give up so fast Jamie. I'm with you on this. Backpack is the only way I'll go also. I once road a 25m. trip with a HD battery for my friend in my pack...and survived. Anyone who's ever weighed a Harley battery, knows these things are almost heavier then a car battery.
And, I still had a place for my girlfriends Tampax....oups, just pulled a Homer.

 

Really? A backpack for cargo? What do you use for gas, a camelback? This issue has been well thought out by many engineers and riders before you.

When Honda engineer a bike to carry stuff, they never come to the conclusion to offer an optional backpack.

Besides, a can of green beans (that will break your ribs when you crash on it) is not really a trade for 52 liters (2 full helmets) of watertight lockable storage. I could carry 2 20 lb turkeys before I put on my 44 or 90 liters of side bags.

Sorry, thats a letter opener to an M16 fight.