So, just a first look for now as I honestly haven't used this bag enough to really review it.  The Arc'teryx website describes the Altra 65 as a "lightweight, multi-day trekking backpack".  I'm not sure that description does it justice.

The Altra 65, resting up on the weight bench.

I had trouble finding these gear loops at first, and thought the bag didn't have any.  Much to my pleasant surprise, there are 4 places where the loops hide with 2 each on the top in two places and  4 each on the bottom two sets.

The loops blend in so well I had to do some fancy Paint editing to show you where the four sets are.

The interior water bladder pouch is well sized, zips securely, has an easy to feed hose hole and a hook for your bladder peering out from the top.

The "U-zip" access gives you access!

"U-zip wide" open.

The harness is  comfortable and breathable, with the really nifty feature of having the hip belt on a pivot.  This really helps with load distribution and makes it easier to keep your balance.  As with all Arc'teryx packs, the suspension is first rate, which was one of the main reasons I bought this bag.  When you have a messed up lower back, its not worth chintzing out.

So far, I've used this bag on one overnight trek into Strathcona Park (Bedwell Lake) and some"utility" use as over built luggage...   I was on quite pleased on that trip as everything fit easily, the pack felt stable and comfortable and the variety of pockets made it easy to stow things you wanted often.  My only real beef so far is the lack of an ice-axe loop.  Then again, Arc'teryx makes many other packs that are more climbing specific, but given everything else they loaded the Altra with, an ice-axe loop would have been a good final touch.  Then again, they wouldn't be able to sell you one for $15 after you've already spent $450 on the Altra now would they...

That's a very nice back-pack!  Day tripping  from Bedwell to Cream lake in Strathcona Park.  The Altra is light enough and compressible enough that if you can leave your gear at your bae camp, it is a very comfortable day pack.

Overall, I am very pleased with the Altra, ice-axe loop aside.  I will be taking it with me everywhere this winter, and will try and fit a couple of more over-nighters or even a longer trek in before coming back with some more review comments.

Happy trails!