What is important to me in a hunting daypack is: LIGHT weight, camo, QUIET cloth, lots of pockets, quick and QUIET access to gear, padded shoulder straps, quality harness, and belt, lots of outside straps, and WATERPROOF. Solid zippers and material that can withstand the test of time are also top on my list...I don't know how many cheap daypacks I tossed because the zippers went out!
You may notice that the top thing on my list is pack weight. You may want to put some of the daypacks you are interested in on a scale....some are 2 to 5 lbs heavier than others. I don't know about you but I'd rather not be lugging that much more weight over the hills...I like to cover lots of country as light as possible!
I'm going to try out a Sitka 45 this fall. It is super light and has many of the features I mentioned above. I've used Badlands for years. They have great zippers, solid materials, great warrantee, and have done me well. I beat my packs to death and have always been impressed with Badlands. The Sitka is a little lighter weight so I plan on trying it out this fall.