I put in 5 miles today in 1:36 with 6 bricks and a 1.5L water bladder in the pack and it is really getting more comfortable as I break it in.

The shoulder straps aren't as soft as my Kelty Redwing 3100 I've been hauling, but I may add a layer of sleeping pad to the underside of them. It's the same stuff I have my bricks wrapped in.

Can't wait to order a Source 3L hydration bladder to replace my 1.5L one with though.

I do find myself wishing that they had put the zippered pockets on the inside of the flap upside down. The ones on my Kelty were right-side-up when the flap was open, upside down when it was closed.

I know the clamshell design of the bag means that you CAN lay it down and open it all the way to get something out, but you shouldn't really HAVE to if you don't want to.