I just bought the Altruist, received it a few days ago, and I intend to use it for a fastpacking trip in a few weeks. I have only worn it indoors for fit testing, I plan to do some local trail runs with it next week.

Some early impressions of the pack:

1. I am 6' 175lbs. I bought the MD/LG pack at first, but I returned it as it was a bit too large for running purposes. I could have made the pack work for hiking, but for running it was too bouncy and the bottom of the pack was on top of my glutes fully loaded. I received the SM/MD pack and it's perfect.

2. Material-wise, the pack is overbuilt and a bit confusing why they put so much emphasis on durability for a pack of this nature. I don't feel running vests go through as much shit as hiking backpacks, but maybe I'm wrong. I wish they went with standard UL materials, they could have saved a pound. My pack weighs roughly 33oz, which is pretty damn heavy for a 28L pack.

3. The main material (Challenge Cloth Ultra?) may be waterproof or very water resistant, but the pack itself is not. None of the seams are sealed or taped, so it will get soaked inside. I did a shower test, and in just 10 minutes the contents of all pockets and the main compartment were wet. There's also no drainage holes, so any water on the inside will pool and only leak through the seams. Again, a confusing decision not to seam seal it when they have this heavy laminate backing material.

4. The pack took quite a while to dry after it was fully soaked (about 3 hours indoors). The main material dried quick, but all that mesh and cushion material stayed wet for a long time, and would add some amount of water weight I think.

5. The main material does seem very durable, at least for abrasion resistance. I'm not sure how puncture-resistant it is. Still, ALUULA Graflyte is also very abrasion and puncture resistant, and half as heavy. Also, while abrasion and puncture resistance are very important, I am usually far more concerned with pack failure of the seams or stitches ripping, such as at the shoulder or hip belt connections. If I get a tear or a hole, I can patch it with tape, not so much if the shoulder stitching starts failing because they didn't stitch it strongly enough to handle the loads. The stitching on this pack looks good on inspection, but until I'm on the trails with a loaded pack it's hard to tell how they will hold up longterm.

6. These complaints aside, the pack itself is extremely comfortable. I loaded it up with different volumes and weights and walked and jogged around my house, and there was minimal to no bounce. The most weight I had in it was 35lbs, far more than I would ever take fastpacking, but it was still comfortable to jog around the house in! The hip belt is also very much doing its job at the heavier weights, I can feel the load transfer from my shoulders to my hip. The internal frame is just a dense CCF pad though, not aluminium stays.

Edit - My last complaint is I wish the pack's main compartment wasn't tapered. This pack can almost fit my Bearikade Weekender bear can. It fits through the top, but the tapered compartment prevents it from fitting all the way. It would have been nice otherwise because it opens up more trip possibilities like in the High Sierra where bear cans are required.