You bring up a good point Jack. I think a lot of people go overboard on the size of a daypack. Unless you are an outfitter/guide or packing your wife and kids in you really don't need a very large daypack.
I disagree with this statement for the type of hunting I like to do. I want a day pack I can put a boned out deer into. I do not want to hike 7 or 8 miles back to my truck to get a packboard and then 7 or 8 miles back to the dead buck. I want to bone him out, put it in my pack and head for the trail head or truck.