I use an Alps OutdoorZ Elite pack. They have an 1800 and a 3800 bag that both attach to the same frame. You can take the bag off to simply if that’s what you need or you can extend it out to make room for your meat you’re hauling out.
The bags have a top compartment for quick access and the rest is one compartment with zippered areas inside and a hydration pouch pocket. The large compartment has a zipper that allows you to completely open it or to position the zipper so as to only access a certain area of the pack. I would be willing to bet the dislike of the MR popup bag has to do with the single top opening.
I hauled multiple deer out with this pack and it hauls wonderfully. The frame has an easy to adjust setup for sizing and the hip belt adjusts accordingly as well. I haul my camera gear and everything else I need with the 1800 pack. I also bought the 3800, but I have yet to break it out.
If I was going to do a backpack hunt for moose, an afternoon Whitetail hunt 3 miles down the road or hike the Appalachian Trail I would grab this pack and whichever of the two bags I needed without hesitation.
Here’s a link where you can scroll through and see the pack frame….
The all-new Elite frame is 30-percent lighter and 30-percent stronger than previous pack frames. In addition, this new frame hits higher benchmarks...
ads.midwayusa.com
Same here for the 3800 bag (the 1800 is identical, only smaller)…..
For multi-day backcountry trips, the Elite 3800 pack bag is the optimal choice. With its 3800 cubic inch capacity, the main compartment features...
ads.midwayusa.com
I’ve only ever seen one other person on here talk about these packs, but they are damn fine packs. I love mine.
ETA:
https://alpsoutdoorz.com/extreme-packs/elite-series.html
P.S. a dove stool fits perfectly around the outside of the 1800 bag and my climbing stick straps easily to the outside.