I have been using a Seek Outside pack for 6 years now. In fact I guess you could call me a collector now. I currently have one revolution frame and multiple bags. I have an ultra old style Peregrine 2800ci, the newer style Peregrine3500ci that is like a small Lanner, a Lanner 5400ci, a Brooks 7400ci, and a old Daypack Talon.
For me this has been the most comfortable pack under heavy loads Ive ever tried, They've been incredibly durable, they are really light for the capabilities and bag sizes, very modular allowing for quick changes at the truck for different hunting scenarios. Ultra customizable fit.
I think a downside that alot of guys run into is they dont spend the time to fully educate themselves on all of the different adjustments that can and should be made to dial in your fit. Just the different frame heights with extensions can make a huge difference. You really have to spend alot of time with this pack rucking with different weights to get it right. Once you have it figured out, its near custom fit for you.
Just as example, If im day hunting, I run the frame at 24", back packing with more weight I run 26", In my kill kit, I always have the 4inch extensions and once Im packing meat those get installed and Im running a 28" frame. When Im hunting with light loads I run the belt semi floating so it articulates with my movements more, when Im packing heavy loads, I lock it down to the frame so its as stable as possible.
The one thing I hate is how strappy it feels all the time. It seems like there are straps everywhere. Sometime it seems like I would be more efficient with better organization and more pockets too but Ill sacrifice that for the lightweight.
It also seems like in recent years they have really culled down the pack options and I dont like alot of the new bags as much though I havent tried them. Sometimes I also wish that the belt was padded better or different but I understand why its not. Its made to be more flexible and move with you more.
Heres some pics of some loads. one is a whole deer. The other ones at night are the heaviest load Ive ever done with it. It was two front elk quarters and all the loose meat off a bull I shot. about 120pounds. It wasnt comfortable because 120 never is but it was definitely doable.