Start with writing down the type of hunts you do now and may do in the future.
Then the tasks you want the pack to do.
As an example:
-We big game hunt North America ( moose to deer sized animals)
-We want while big game hunting to be able to switch from a light day pack to a 4000ish CI pack for spike outs.
-We also want the ability for elk and below sized game to get back to camp with at least a bone in cut at the knee rear quarter and grind / backstraps/ loins.
- We want that same pack to be downsized for day hikes/scouting trips/ turkey hunts.
-Lastly I want the same pack to easily rig down to a bare bones freighter that holds a nalgene bottle to haul meat only out.
A hand full of packs fit the bill as explained above. As others have said though fit to you while load carrying should be the deciding factor. Best to try a bunch on.
I've sold a lot of packs for a company while in the woods when I let someone try mine for a couple hundred yards

I should get a kick back or freebie or something
