Free: Contests & Raffles.
If the Osprey works for you, I see no reason to buy another pack.
Just pick up a lightweight liner bag from Sea to Summit to put your meat in so you don't bloody the pack up.
I think the most important reason for using a pack made for hunting is that they are made to be quiet. Maybe your style of hunting doesn't require a quiet pack. And if that's the case you probably don't need the camouflage color either.
No need. I use hiking packs, an Alice pack, a "hunting" pack and pack frame. Just depends on what terrain, distance and type of hunting. 1st load with whatever I got then pack frame. To silence your pack use electrical tape. Use 1 hand and shake your osprey, wherever you hear noise warp it a couple of times to silence. Then if you need to take it off it peels of easy.