My son, a thin, 11 year old ---is 56" tall
The Synapse 25 and a Brain Bag....
This is becoming a real dilemma for him.
The BB is rather wide for his frame- but he likes the two compartments and how lazy he can be about packing it properly --36 liters is more than he needs by a factor of 2.
The Synapse 25 (the more elegant option in my opinion) would require (20% of the time) him to be more careful placing items in the pack.
80% of the time he would not need to fill the Synapse 25 "all the way".
But like a true bag addict, he can see a reason to keep both....
The red bag in the photo is NOT TB, and frankly, too small for the things he needs to bring.
Both bags are packed with a GIANT zippered binder (required by the school), a set of gym clothes, an iPad- standing in for a netbook (provided by the school) and a tupperware container -standing in for a packed lunch.