This yellow peril's very short in the back and stable, even when heavily loaded. The waist belt wings cinch down snugly onto the hips, with pockets keeping snacks close to hand for on-the-fly feeding.
The bladder sits neatly in a sleeve at the back of the main compartment, while a pump sleeve, extra zip pockets and bellows expansion make it a real Tardis of a pack. The Velcro hose guides are a particularly neat trick - no more trying to force 90-degree valves through narrow sleeves.
The soft mesh back keeps things cool even when it's not, and we could only quibble with the slightly scratchy shoulder straps a tiny bit, but that's all.