I have had this pack for quite some time now. I plan on returning it for something larger.
Since Ive had time to adequately test this bag, Im going to throw down a straight-forward review for those of you considering the Stratos 24.
Make no mistakes this pack is great. It's well designed and when it comes time to perform, it does not disappoint--to a degree. The name of the game here is day hikes. Some people have written that they can fast-pack or rock a minimalist over-nighter out of this pack. Some people even claim they can go up to three days out of it. I call shenanigans. With the compression straps loosened all the way, I can fit either a fleece or soft shell, first aid kit, 2 liters of water, one day of food, my headlamp, a spare knife, a role of duct tape and a small amount of cord into the main compartment. If I'm extra careful, I can also get a water filter in there. Recently I used it for an over-nighter. I managed to fit my sleeping bag, one beer, an extra layer, my headlamp, and a small first aid kit. In the top mesh pocket, I can fit my wallet, a pen, a small moleskin, and my ipod or camera and my keys. Originally I used this pocket for sunglasses but on a short hike with a loaded pack, I reached for my glasses at the end of the day, only to find that they had somehow been smashed and irreparably damaged. Now, eye wear stays on my face when this pack is on. The other small pocket on the top is useful for miscellaneous items, but with a full pack its difficult to load or retrieve anything. The pockets on either side of the lumbar straps are very cool, and quite handy. I generally reserve the left one for trash (mine or whatever I might find along the way). The right one holds anything from snacks to gear I may need to access quickly. In addition to that, there is a pocket located on the right shoulder strap for your phone or gps. An iphone will not fit. Any small brick phone will fit wonderfully and securely, and access is easy. I really love this feature.
Another feature I particularly like is the rain cover and stash pocket for it. Located towards the bottom of the bag, above the gear loop is a small zipper. Unzip it and pull the rain cover out, and wallah! Dry bag. That being said, its not totally waterproof and pressure points will allow water to get through in heavy rain. No big deal though, unless you deal with downpours on the reg.
The gear loop on the bottom of the bag is pretty useless. An ice axe will fit well, and there is a small elastic snap mid way up the bag to secure the shaft and keep it from wriggling loose. You might also be able to carry a pack shovel with this feature, but do so at your own risk. I attempted and do not recommend it, but with the right handle, your shovel will stay put. Frankly, I would not attempt to ski or mountaineer out of this pack.
The airspeed back panel is a pretty nifty feature. On hot days it makes quite the impression. However, if you're expecting a sweat free back, you'll be sorely disappointed. The AirSpeed system makes a difference to be sure, but your back still sweats, albeit to a much lesser degree than with other packs. This system also presents somewhat of a catch-22. In designing the pack to breath, and choosing to do so with a fixed external frame, Osprey drastically limited the carrying capacity of this pack. Simply put, the frame basically makes it impossible to carry books or a laptop because of the concave shape of the frame. It is nice however, to be able to throw gear wantonly into your bag and not worry about a lumpy mass digging into your back.
The shoulder straps are comfortable and this pack features adjustments normally saved for much bigger packs. The lumbar strap system works well, though the straps are much too long for my tastes and serve only to get in the way. The chest strap works well, and the whistle in the buckle is a welcome sight. Comfort and adjustability aside, if you overload this pack (which is easy to do) you will suffer mercilessly. I've been using this as a crag pack for the six weeks now, and if Im honest, its a hellish ordeal to try and carry anything more than my draws, harness, shoes and chalk bag. I fandangled my rope onto the top of the pack via the two cinch straps located posterior to the shoulder straps, but anything more than a mile or two becomes unbearable and I have to stop and take my pack off. I recommend keeping it below 25lbs whenever possible.
Inside the main compartment is space for a three liter water bladder and dual port holes (left and right) to feed your hose out. There is no dedicated hose holder, however both straps have elastic bands which can be used to keep a hose well out of the way. There is a strap to hang your bladder located against the back panel of the pack, but accessing it is a a nightmare, and the top mesh pocket needs to be empty if you seek to stand any chance of securing your bladder. Also note that due to the shape of the frame, pack space is eaten up by a fuller bladder and its very easy to place un-due pressure against it.
This pack is light and sturdy, and for anyone looking for a very solid day pack, this would be a worthy addition to your gear selection.