If you haven't decided yet, I'd definitely look at Seek Outside. By far the best pack I've ever worn--especially under heavy loads. Just finished my 4th season with mine and haven't had any issues with it whatsoever. My opinion is that you probably can't go wrong with any of the higher end packs on the market today (EXO, Stone Glacier, Seek Outside, Initial Ascent, etc.). For me, Seek Outside checked off the most boxes, and here is why I decided to pull the trigger on them:
I did a ton of reading, watching videos and research on all of the different pack brands. I called in and emailed each company and drilled them with questions. The two main things I was looking for was a pack that was lightweight and could handle a heavy load really well.
What pushed me over the top on Seek Outside was the following:
1. Lightweight. Starting at sub 3lbs, all their packs are sub 5lbs.
2. The fabric they make their packs out of (X-Pac) is a premium, durable AND waterproof material. This means no need for a pack cover when it rains and no blood stains with easy washing. You can actually take the bag off the frame and hand wash it or throw it in a front load machine if you want.
3. Their suspension system/frame. Instead of using the same frame idea that is already out on the market and trying to improve it like most pack companies out there, they started over from the ground up doing their own system. The frames are very well built...they can support 300lbs in vertical load yet weigh only 6oz. They are also very versatile in that you can have multiple pack bags and switch between smaller and larger packs if needed. I ended up doing a custom build and took certain things I liked from a couple different pack bags. But, it's nice to know I could just buy a different pack bag and switch it out if needed.
4. Adjustable frame height. 24, 26 or 28" frame height. Having the ability to adjust your frame to be taller if you get an animal down makes the pack out easier.
5. Very configurable. Not only are they good for hunting, but you could use them for backpacking, pack-rafting, ski mountaineering, etc.
6. Excellent customer service. They have treated me very well and are super nice and helpful.
7. Made in the USA.
Just my two cents. Again, I don't think you could go wrong with any of the other packs I mentioned above. I think they are all great. Seek Outside just checked off the most boxes for me and what I was after. I've been very pleased with my decision so far.