This is a quick comparison between The Brown Buffalo ConcealPack 21L and the previous 19L (v3) based on initial impressions.

Why Another ConcealPack

I got my ConcealPack 19L around the time when it seemed like The Brown Buffalo might go out of business. Even though I considered the canonical color/material for the ConcealPack to be black ballistic nylon, I was only able to pick up a Multicam Black (MCB) version at the time.

When the 21L version came out, I liked the idea of the clamshell opening and liked the fun colorful interior. I always felt the 19L was a little tight and so thought the 21L made sense. So when a discount showed up for the 21L, I jumped at the opportunity.

Size

When viewed side by side on the ground/a table/in photos, the difference seems kinda subtle. The difference in size was more noticeable on my back. The 21L seems to be a bit taller, and maybe just a little bit more in other dimensions. It definitely feels larger on my back (I was hoping I wouldn't really notice the difference).

I tested my current work load and it definitely fit more comfortably with more room to spare. I think the greater pliability of the VX used for the interior bucket pockets also helps.

The back "conceal" pocket feels a little larger than the one on the 19L but requires similar precision maneuvering to get my 15" MacBook Pro in. Maybe the opening is still the roughly the same size.

I generally prefer my day use type bags to be about 20L. But different 20L bags can feel very different.

"Feel" Size on My Back (Smallest to Largest)

Bedouin Delireis SE (20L)
Outlier Ultrahigh Rolltop (20L)
The Brown Buffalo ConcealPack 19L
The Brown Buffalo ConcealPack 21L

"Feel" Capacity (Smallest to Largest)

Bedouin Delireis SE (20L)
The Brown Buffalo ConcealPack 19L
Outlier Ultrahigh Rolltop (20L)
The Brown Buffalo ConcealPack 21L

I'm always amazed by my Outlier. It packs down really small, is super light, and yet feels like it can hold so much. It is, of course, a much more minimal bag (unlined, etc).

The ConcealPack 21L definitely feels like a larger bag and comparisons elsewhere often compare it with 24L and 26L class bags.

Clamshell Opening

The clamshell opening definitely makes it easier to throw the pack down, splay it open, and get stuff in and out.

As part of the change, main zipper was moved closer to the front face of the pack. On the 19L, the main zipper is at about the midpoint between the front and back faces of the pack. Because of the new placement of the main zipper, it does make it more difficult to get a laptop in and out of a sleeve attached to the back panel because of the additional "lip". I'll have to see if this is something I just get used to or discover a trick/technique for.

Lining

The lining on the 21L is a X-PAC/VX fabric and kinda 90's fluorescent/ski jumpsuit colorful. The lining on my 19L is a gray Cordura.

Because the VX feels thinner and more pliable, it feels less attached. I'm sure it is just as well attached as the Cordura lining on my 19L. I think the stiffer Cordura in the 19L just made that less noticeable.

My 19L feels stiffer but not sure how much of that is attributable to the additional Cordura lining as opposed to the exterior 1000D Cordura (19L) versus the 1050D ballistic nylon (21L). I do like the feel of the sturdiness of my 19L.

Thoughts

I've moved my work gear into the 21L for the time being and will use it as my "main" bag for the near term. The black ballistic nylon will be more "professional".

I was contemplating selling my 19L prior to receiving the 21L but I think will keep it around as a more compact, more casual "go-out" pack (for going to the park/zoo/fair/etc). I usually use my Delireis for that purpose so those two can split duties. I don't like the straps on the Delireis as much as on the ConcealPacks.