REI Trail 40

Pros

• Effective load-transferring harness and suspension system for superior comfort.
• Large front-panel opening allows for easy access to the main compartment.
• Available in multiple torso lengths, gender-specific versions, and plus-size harness options.
• Generally compliant with overhead carry-on standards for most airlines.
• Includes a built-in rain cover and is relatively lightweight for its capacity.
• Versatile enough for both wilderness hiking and urban air travel.

Cons

• The frame height (approx. 21-22.5 inches) can exceed strict airline limits if the top pocket is overstuffed.
• The 'S' style shoulder straps may not be comfortable for all body types; some users prefer 'J' style straps.
• Difficult to acquire for travelers located outside of the United States (e.g., Europe).

Caveats

• While some users attempt to use it as an under-seat bag when underfilled, others strongly advise against this due to the rigid frame and bulky hip belt.
• Meeting strict budget airline sizers (like Ryanair or Iceland Air) requires careful packing and compression of the bag's depth.

Best for

• Hybrid trips involving both air travel and significant hiking.
• Travelers who prioritize a comfortable, technical suspension system over aesthetics.
• Users who struggle to find a one-size-fits-all bag and need specific torso or harness sizing.

Avoid if

• You are looking for a dedicated personal item or under-seat bag.
• You prefer a bag without a rigid internal frame.
• You live in a region where REI products are not easily shipped or serviced.