Took this on a quick hike last weekend and it stayed put the whole time, no bouncing around. The crossbody strap adjusts easily and the whole thing is slim enough that it doesn't feel bulky against my back.
Hannah★★★★★
The strap sits soft against my shoulder even after a couple hours walking around, and the crossbody fit keeps the bag from swinging when I bike to class. It holds my phone, keys, and a water bottle without feeling bulky at all.
Zoe★★★★☆
The soft back panel sits nicely against my hip on the walk to class, and the sling stays put without bouncing. Only gripe is the main compartment is a bit tight once I add a water bottle, but for phone, keys and a snack it's ideal.