It unfortunately doesn't have the same airspeed back to allow air to your back so I'd say it's likely to be much hotter on the back.

Having used both for international travel, I'd say that the vented backpanel is really noticeable if you were to have the pack on your back for >1hr at a time--so in backpacking situations. With international travel, you tend to carry your pack for maybe 30min at most between hostels, on and off buses, etc... I would say the ventilated backpanel on the Aura was nice but I didn't notice it as much as how light in general the pack was in comparison to when I packed with the Ariel.

The real difference would be whether your wife wants something that will structurally carry 30lbs better or something that is lighter-weight? If she wants a lighter-weight pack and is willing to compromise a little on how well it carries, then go Aura. If she wants a more comfortable carry and is willing to compromise a little on ventilation and weight, go Ariel.

Thanks for the info! We're going to be hiking the Camino de Santiago in July. This will be our first time, so I'm not sure how long of stretches we'll be hiking at a time, but I'm guessing they will be longer. From what you're saying, it sounds like the Aura will be the better choice for her? I see the new Aura has just been released for 2012 with a higher recomended load carrying capacity. Maybe that will be the best option, with the vented back and better load carrying. Thanks again!