I've been using Eberlestock Dragonfly and Blue Widow. Then I saw this pack. It's on my list of "new gear for 13' ".
Stone Glacier Ultralight Backpacks
The guy that designed them knows a few things about extreme lightweight hunting "go in light come out heavy".
I've pushed the limits on Eberlestock packs hiking out with Moose hind quarters pushing 100 lb. plus. I've started testing packs by using 25 lb. sand bags and progressing to 100 lb. to see where the comfort levels of the packs are and the weight limits of the packs.
Think about if you ever do a solo hunt and have to carry everything with you that you'll need then carry out a boned out animal. Or possibly a time where you will hike Moose or Caribou quarters over several miles or a large Brown Bear hide. Find a pack you like and see if you can borrow the model your looking at buying or see if the manufacturer will loan a pack out to test.