I always keep nagging when I just carry this Lowepro backpack for cameras, because of instant and frequent access I need and it doesn't provide. So it is so helpful for the back if loads are devided into sides instead of back. BackTpack promises to improve posture and strength. besides all the benefits of Tpack, there are some points to take more serious: what if right bag is more loaded? and also I dont see free hands when I am carrying Tpack. It seems a bit more functional. Since back no more plays role in carrying the bag, I guess it should have been called "Sidepack"!