I chose this pack after my friends have always raved about Gregory products....I also looked the Osprey Ariel but found the Gregory to be of superior fabric quality and better features.
I bought this pack before traveling to Papua New Guinea on a 2 month research trip (littered with weekend bush excursions). I used this bag as my carry on luggage and packed it as full as I could possibly carry perhaps 50+lbs. It fit on every domestic and international flight I took, however when getting into Australia they restrict the weight of carry-ons...so it had to be checked for this leg of my 5 flights. During my 48hours of flights I found the extra access pocket on the front and the side stash pockets to be incredibly useful for my ipod, water bottle and constantly changing layers of clothing according to the cabin temperature fluctuation. Lugging 50+lbs was surprisingly easy as the weight was comfortably distributed on my hips
In the country, I hiked Mt. Wilhelm, the highest point in the country, with the Deva and it preformed spectacularly! It comfortably fit my sleeping bag, 3 days of clothing, multiple bottles of water and various other pieces of gear. Plus the many loops were helpful to strap down random pieces of needed gear. The waist band pockets were very handy to keep my digital camera, sunscreen and lip balm with easy access. Only thing I would recommend would be purchasing the rain cover...it poured on our climb to the base camp of the mountain... My sleeping bag at the bottom of the pack was pretty dry, however some of my clothes which had direct contact with the front of the pack got a bit damp. My fault for not preparing for the rain forest weather.
The overall construction of this pack is very well made...on my way back to the states I packed tons of tribal art pieces, an other souvenirs from my trip and checked the bag as luggage. The fabric held up extremely well through all the flight transfers and customs checks! I really can't say enough good things about this pack, definitely worth the money and I look forward to many many more adventures with it!
I am 5'8 and 140 and the medium seems to be the perfect fit for me :-)