Was given this backpack as a gift, and I haven't used it quite yet but it has everything I need out of a summit pack. The 38L capacity is perfect for a full rack of gear, some food and extra layers with straps for ice tools, helmet, and crampons. The back support can be removed so it can be thrown into my larger pack for expeditions. Can't wait to use it!

This is my first quality pack (was a gift from my GF for my birthday), and I choosed this model because I do rock climbing and I'm planning to do some light mountaineering soon, so it looked like this was the best option for me, but I should probably had to choose a different model. This is why; I've had my 38L for 3 months now and I use it every weekend to carry my climbing equipment to the crag and it is great for that, it is a very nice pack, the material looks like is going to last forever but there are a couple things I don't love about it. 1. SIDE STRAPS. it has a strap to hold your rope on each side, I'd love to have those placed a few inches lower, they are located very high on top and the hanging loops of the rope move all around when you are walking or ... MoreThis is my first quality pack (was a gift from my GF for my birthday), and I choosed this model because I do rock climbing and I'm planning to do some light mountaineering soon, so it looked like this was the best option for me, but I should probably had to choose a different model. This is why; I've had my 38L for 3 months now and I use it every weekend to carry my climbing equipment to the crag and it is great for that, it is a very nice pack, the material looks like is going to last forever but there are a couple things I don't love about it. 1. SIDE STRAPS. it has a strap to hold your rope on each side, I'd love to have those placed a few inches lower, they are located very high on top and the hanging loops of the rope move all around when you are walking or approaching, getting stuck on trees etc, It has a couple of compresion straps below, and I use those to secure the rope but those dont have clips and is very difficult to put the rope inside them. 2. SIDE POCKETS. You can carry watter on your internal reseirvoir and that's ok, but if you are carrying coffee or something else in another bottle the only place you can put that is inside of the pack, not very convenient if you want to drink that on a quick break during your walk to the crag, you need to put the bag in the gound, open it, take out your stuff to get your coffee out, then put everthing inside again to continue walking. Every weekend I have to choose if I carry my coffee in my hand or go thru all that. 3. BREATHABILITY. If you are walking in warm days you will probably end with a sweaty back, there is not a lot of breathability in that area of the pack. As I said, probably another osprey model would be better for what I need, but that is my experience so far.

I fret over packs. I routinely destroy packs through use. This thing is the closest to perfection I've seen after 10 years of climbing. I previously shied away from Osprey packs because they've always seemed over-engineered and a little too ultralight (i.e. delicate) to me. But I'm really glad I went with the Mutant 38. I got it to replace my Cold Cold World Valdez, which is bomber but doesn't carry heavy loads very comfortably.I wanted something small enough to climb with, but big enough to fit everything for 2-4 day routes (with judicious packing). After a summer of abuse in the Cascades (including two nights on Stuart's North Ridge and a day of using it as a haul bag on Liberty Crack), I'm as convinced as the reviewers at OutdoorGearLab, who fawned over ... MoreI fret over packs. I routinely destroy packs through use. This thing is the closest to perfection I've seen after 10 years of climbing. I previously shied away from Osprey packs because they've always seemed over-engineered and a little too ultralight (i.e. delicate) to me. But I'm really glad I went with the Mutant 38. I got it to replace my Cold Cold World Valdez, which is bomber but doesn't carry heavy loads very comfortably.I wanted something small enough to climb with, but big enough to fit everything for 2-4 day routes (with judicious packing). After a summer of abuse in the Cascades (including two nights on Stuart's North Ridge and a day of using it as a haul bag on Liberty Crack), I'm as convinced as the reviewers at OutdoorGearLab, who fawned over it.Volume: It may advertise as 38 liters, but this thing is a bottomless pit. It took sleep kit, food for 3 days, 2.5 liters of water, a single rack, extra clothes, etc. without batting an eye, and it was still comfortable for a long approach.Climbing: Just as important, it climbs really well, even with the frame in, so you can keep that internal structure for a long approach without it being uncomfortable when things get vertical. I really liked the extra hood feature that covers up the top of the pack when you stuff the brain inside -- it keeps moisture out and gives the big cinch straps a place to go instead of just dangling.Cons: The cons are pretty minor here. I agree with Connor that the attachments are a little fiddly when using more technical/aggressive tools. Also, the cinch straps for the brain run directly over the handle attachments for your tools, which ends up being pretty annoying (and is the reason for 4 instead of 5 stars). Finally, there is absolutely no internal organization to this pack, except for a hydration sleeve. I actually prefer this, but it's something to keep in mind if that matters to you.