Seems im in the minority but unless the pack is made out of bubble wrap it should be quiet enough.
I personally need a pack that is as light as possible. strong as possible and preferably not camo. I set my pack down when blood trailing, and other times and i dont like having to fight to find it becasue of the camo.
The shape of the pack is also ver important. it needs to be narrow for hunting in the thick woods, nothing worse than snagging your pack on branches. also has to have compression straps so i can tighten to load to my back, again to avoid snags.
Also important to me is fast drying. I hunt in the rain and i need a material that drys very fast.
So for me a light weight, tough as nails, narrow, compressable, non camo, fast drying pack is at the top of my list. Quiet is down the list a long ways from those items.
Good news is they make packs that cover anything and everything a person is looking for. But for me its more along the lines of mountan bike packs than hunting packs.