I have never found the airspeed / airscape type Osprey suspensions worth beans. Yes, great for ventilation, but suspect in keeping any load close to your back / center of gravity where it should be. Having said that, that was with older versions. I believe Osprey had reduced the bow in those suspensions.
The Osprey Aether series is really nice for heavier weights but overkill and quite heavy for loads under 30 lbs (the original Aether 60 was 3lbs, 6oz. The new one is almost 2lbs heavier).
However, the Circuit is an amazing pack for loads under 30lbs. Yes, it can carry loads higher than that and will not implode, but it has a sweet spot on the other side of 30 lbs. The belt is possible the best in the business short of Mchale - for all available packs. Wide, supportive, not too thick with dual buckle adjustment. The shoulder straps are nicely padded and wide, and the delron hoop does a really good job at load transfer to the hipbelt. All this for just over 2lbs!