When comparing Gregory J38 vs REI Trail 40 Pack, the Slant community recommends REI Trail 40 Pack for most people. In the question“What are the best carry on backpacks for travel that hold at least 30L?” REI Trail 40 Pack is ranked 3rd while Gregory J38 is ranked 9th. The most important reason people chose REI Trail 40 Pack is:
There is a [women-specific version](http://www.slant.co/topics/5119/viewpoints/7/~carry-on-travel-backpacks-for-women-that-hold-at-least-30l~rei-trail-40-pack-women-s) of the REI Trail 40 available, which has a slightly smaller torso fit range.
Ranked in these QuestionsQuestion Ranking
Pro Women-specific fit
The suspension system and harness is designed specifically for women. The torso fit has a range suitable for shorter backpackers as well.
Pro Integrated rain cover
The pack includes a color-matched, quick-attach rain cover.
Pro Very well built
Gregory is known for their very durable and well designed bags.
Pro Women-specific version available
There is a women-specific version of the REI Trail 40 available, which has a slightly smaller torso fit range.
Pro Pockets on the hip belt for easy access
The hip belt has two zippered pockets which lets you store things for easy access (such as papers, money or snacks).
Pro Four zipper access to easily get to your belongings
The pack is front load with four zipper access, allowing you to unzip from either the top or bottom. This is great if you want to grab something from the bottom of your pack without opening it completely.
Pro Includes raincover
The pack comes with a rain cover that stows away in it's own zip pocket.
Con Not specifically designed for travel
The J38 is a versatile pack, but not specifically designed for travel. It has some features you may not have a use for (such a pole loops) and is lacking in features you may find helpful (like a laptop sleeve). The shape is not ideal for storage (under seats, or in the overhead).
Compared to other packs around this size, the price tag on the Gregory is a bit higher.
Con Pocket for hydration reservoir is difficult to access
The pocket for the hydration reservoir is external, located right behind the back panel. There is very little room, making it hard to access and can only fit a small amount of water (around 1.5L).
Con Internal bungee compression system can get in the way
The internal compression straps are a bungee system, which does not unclip the way most do. When your pack is full, this can make it a very tight squeeze if you want to access something in the back.