It works well, and I left off the 5th star only because the straps don't have a chest-level cross-latch.  Some might find this picky, but when you have 4 gallons of chemicals on your back, that weight tends to pull the backpack off your shoulders.  As a 5'3" tall woman with good upper body strength, it adds stress to my back.  My solution was to hand-fashion a cross latch with Velcro and nylon strap.  Problem solved