I don't just hand out 5 stars on a review, unless a product truly deserves it. This pack falls into that elite group of gear that is near perfect in its design. The Southwest 2400 from HMG is a workhorse of an ultralight pack, and is ideal IMO for the experienced mountain enthusiast who requires going fast and light.
I'm 6'1", 175lbs, and went with the large in white. The white and black options differ in strength/durability of the dyneema used in construction. I chose white for the best weight savings, and found it to be plenty burly for my most recent trip - a 7 day thru-hike across the Uinta Mountains in eastern Utah.
I started with 30lbs of gear on day one, and initially was worried with the pack fit/comfort. I remembered a review that mentioned the pack needs a couple trail days to "break in" and shape to your body, and I found this to be true. By day 3, the pack was honestly one of the most comfortable packs I've ever used in 12 years of mountain travel. Impressive for how minimal it is.
In the mountains, I believe simplicity is king. This pack is exactly that - simple. It has one main compartment with a roll top closure (great because it makes the pack waterproof, so no need for a pack cover), 2 hip belt pockets for frequently-used items, and 3 stretch pockets on the sides and front of the pack that are perfect for water bottles, tent/trekking poles, bear spray, maps, jackets, etc.
1) SO LIGHT - only 28.6 oz in the size large so ~1.9 pounds
2) Ultra durable for the weight - this thing is tough (dyneema is amazing)
3) quality craftsmanship and made in the USA - big ups to HMG for this!
4) 2 aluminum stays in the back panel provide good stability and carry for an ultralight pack in this category (major reason I chose this pack over others)
1) the back panel is also made of dyneema, which does not breath, so my back got pretty sweaty. Honestly, not a big deal, because I sweat with any backpack, but there was no real airflow behind my back to help alleviate this. Minor IMO compared to how great this pack is.
I foresee using this pack not only for UL backpacking, but also for mountaineering/alpine ascents, and even ski touring in the winter. I'm thinking of keeping it packed as a SAR bag for searches in the winter when patrolling - no time to deal with bells and whistles when someone's life could be on the line.
Bottomline: if you consider yourself an experienced mountain traveler, don't need frills, and you are looking for an ultralight pack to accomplish pretty much any objective, this pack will get you to the end of the journey and back.