This 35 liter example from the Less Is More series is full of smart detail.
Airback carrying system with great airflow
bluesign certified 70D*140D diamond ripstop polyamide
Side stretch pockets
Hip belt pockets
Space and ports for a hydration bladder and hose (not included)
Front panel elastic for overpacking and compression
Flap pocket
Chest strap
The hip belt is wide and well padded