Real owners lean toward the Gregory Zulu 55: 88% of 25 owners recommend it, vs 78% of 190 for the Osprey Atmos AG 65.
Verdicts aggregated from Reddit, enthusiast forums, and YouTube owner comments — affiliate reviews excluded. Sample sizes differ; judge accordingly. How we score
Both packs earn praise for comfortable carry of heavier loads and a ventilated back, so owners cross-shopping the Atmos AG 65 and the Gregory Zulu 55 start from a lot of common ground, including that neither is a lightweight choice. Atmos AG 65 owners credit the Anti-Gravity suspension for making 35-40 lb loads feel lighter and keeping the back cool, backed by Osprey's warranty, while flagging its near-5 lb weight, a hip belt that softens past about 40 lbs, squeaking, and small hip-belt pockets. Zulu 55 owners describe an effortless carry, an adjustable torso and shoulder fit that suits many body types, and generous capacity, though they mention it being heavier than ultralight packs, too many buckles over few compartments, and that newer models dropped the rain cover. A backpacker who wants the load-shifting suspension and lifetime warranty leans Atmos, while one who values adjustable fit and simple big-volume packing leans Zulu 55. The decision hinges on suspension comfort versus fit range and organization.
“Got a Zulu 55 early spring and have taken it on a number of 2-3 day backpack camping adventures.....love the pack!!!!”— @va3ks on YouTube
“is an excellent pack which I use for almost all of my overnight trips these days”— WeAreThePizza on Reddit
“Gregory's decision to stop including rain covers is such a dirty shrinkflation move. They took out the bungee sunglasses holder on the shoulder straps too.”— @GetUpTheMountains on YouTube
“Highly recommended”— @LowGearHiker on YouTube
“Definitely worth the price they have an unbeatable warranty”— @anthonygolden3685 on YouTube
“I had the Osprey Atmos AG 65 backpack, Naturehike Cloud Up 2 tent and an REI sleeping bag - all of which were really heavy. I have since started to buy much lighter gear.”— The_Light_Explorer on Reddit
Both packs earn praise for comfortable carry of heavier loads and a ventilated back, so owners cross-shopping the Atmos AG 65 and the Gregory Zulu 55 start from a lot of common ground, including that neither is a lightweight choice. Atmos AG 65 owners credit the Anti-Gravity suspension for making 35-40 lb loads feel lighter and keeping the back cool, backed by Osprey's warranty, while flagging its near-5 lb weight, a hip belt that softens past about 40 lbs, squeaking, and small hip-belt pockets. Zulu 55 owners describe an effortless carry, an adjustable torso and shoulder fit that suits many body types, and generous capacity, though they mention it being heavier than ultralight packs, too many buckles over few compartments, and that newer models dropped the rain cover. A backpacker who wants the load-shifting suspension and lifetime warranty leans Atmos, while one who values adjustable fit and simple big-volume packing leans Zulu 55. The decision hinges on suspension comfort versus fit range and organization.
Owners point the Gregory Zulu 55 at backpackers who prioritize load comfort over minimal weight, and multi-day and overnight trips with heavier loads.
Owners point the Osprey Atmos AG 65 at multi-day and thru-hikers carrying loads around 30 to 40 lbs, and sweaty-backed hikers wanting the ventilated anti-gravity suspension.
The most-cited downside of the Gregory Zulu 55 is heavier than ultralight packs. For the Osprey Atmos AG 65, it's heavy for its class at roughly 4.5-5 lb empty.