I've owned two Ogio Crunch duffels since 2009, both purchased via Amazon.  The first lasted 5-1/2 years; the second only 2-1/2 years.  I used them as a gym bag and a briefcase.  Everything from my workout clothes to lunch bag and coffee, as well as work papers goes in the bag.  When my latest Crunch bag wore out I shopped around for a new one.  I'd been disappointed with how the second Crunch bag wore out quickly v. the first I owned (see my review for the Crunch on its product page.)  I was ready to abandon Ogio for a different manufacturer.  I looked at the following bags:

Adidas Team Issue (58 liters)
Ogio Crunch (49 liters)
Under Armour Undeniable Medium (56 liters)
Ogio Big-Dome (55 liters)
Ogio All-Terrain (40 liters)

Frankly, I doubt the listed capacity figures for the UA and Adidas bags.  I compared them side-by-side with the Crunch and both appeared to have the same capacity or were slightly smaller.

I chose the All-Terrain, even though I gave up nine liters of capacity relative to my old Crunch bag.  Essentially, I was willing to give up some space in order to have better-quality fabric, double zippers on all pockets, more pockets, and a slightly shorter bag that makes sitting on the bus and train next to people easier than with the larger Crunch bag I had.  Plus, the All-Terrain seems to be a bag of higher quality than the other four.

The detailed reasons are as follows, compared with the other bags.  I've included some photos, too, including side-by-side comparisons of my old Crunch bag and the new All-Terrain one:

The fabric on the All-Terrain is thicker nylon, the stitching seems stronger, and the zippers seem better.  On my Crunch the failure points were the zippers (one failed on each bag after long periods of use) and, in addition on my second bag, the bottom, which cracked and wore through to the underlying mesh.  The All-Terrain has double zippers on the side and two end pockets, and the top opening (i.e., all pockets except the small "media" pocket.)  The side pocket is deep and contains two interior elastic mesh pockets.  On the other side the "media" pocket is useful for quick access to my keys and work ID / train card while I'm commuting.  The bottom is thicker and more solid than the Crunch's, though not rigid.  It's similar to the Adidas Team Issue bag's bottom.

I commute by bus and the DC Metro train to work.  It's easier to sit next to people with this slightly shorter bag, and to navigate standing on the train and through stations with a slightly smaller bag.  I've been using it for two weeks now.  I really like it.  The side pocket with interior mesh pockets and double zippers is more convenient than the Crunch's side pocket, which only had one zipper and no interior mesh pockets.  It's easy to get at my phone, a small book, Kindle, or iPod in this side pocket.  The "media" pocket that I use exclusively for ID and keys is really easy to access, too, as it's at the top of the other side.

The end pockets are much the same as on the Crunch.  One of them is a shoe compartment.  The shoes extend into the bag so take up some room there but that's not a problem for me.  I've been carrying the same mix of gym clothes, lunch bag, coffee travel mug, work papers, and some office odds and ends in here as I did in the Crunch.  If I used this bag to carry my shoes back and forth every day it might be too small.  As it is, my shoes, weight belt, lifting chalk, toiletries, etc... are in my office because my gym is in my office building.  I'd need a bigger bag if I were carrying those things back and forth every day.  Then again, if that were the case, I'd probably just rent a locker in the gym and keep those items there.

If this bag were 4 liters bigger (say, 44 liters v. the 49 for the Crunch) it would be the perfect gym bag for me.  As it is, I was willing to give up some capacity for better construction and pocket features compared with other bags at this price point.  After two weeks of use, I'm not missing that extra space yet.  The Adidas and UA bags seemed flimsier even though they get great ratings on Amazon.  The zippers, in particular, seemed to be of lower quality, and the fabric was thinner.  The Ogio Big Dome bag has limited pocket features, which is why I didn't buy it.  And the Crunch may be bigger, but I like the features of the All-Terrain better.  The All-Terrain also seems to have more robust construction compared with the brand-new Crunch bag I ordered and returned after comparing them.  Also, I can fit the All-Terrain into my gym locker easily, whereas with the Crunch I had to, well, crunch it into the locker.

Some have complained about the molded plastic two-piece locking handle on the Ogio bags.  The Big Dome bag doesn't have these; it has a conventional Velcro fabric wrap handle.  The Crunch and All-Terrain bags do.  I really like the plastic handles and disagree with those who mock them.  They're an excellent design feature.  They work very well and make the bag easy to carry without gouging the hands as the Velcro handles tend to do.  The handle straps are robust, too.  The Adidas and UA bags have the conventional Velcro wrap handles.

The one feature on the All-Terrain that's of lower quality than the Crunch bag is the connection for the shoulder strap to the bag.  On the Crunch it's a metal clip attaching to a metal ring.  On the All-Terrain its a plastic/metal clip attaching to a plastic ring.  This might be a weak point down the line; however, I rarely carry the bag on my shoulder.

The All-Terrain is a solid, if smaller, gym bag for daily use at this price point.  I'm really enjoying it so far, even though I've given up 9 liters of capacity v. the Crunch.  This would be a small weekender duffel bag for travel compared with the others.

I'm also doubtful that moving up to the $100 price point for a medium-sized duffel would be better value in terms of features and wear.

I'm very happy with the All-Terrain so far.  I don't give it five stars solely because of the reduced capacity.  Every other feature, however, pleases me.

Update (May 1, 2018):  I've used this every day for two months as my briefcase/gym bag.  Despite my initial concerns about the size (smaller than the Ogio Crunch I'd used since 2009) this bag is absolutely the perfect size for me.  I love it.