I guess I can update this thread to say that I'm more than happy with my Eberlestock Just One pack. It packed out 3 elk and a mule deer this year without a hiccup.
This load ended up very low, but it was more due to my poor packing skills than any fault with the pack itself.
It was the head plus a front shoulder plus everything that started out in my pack (I killed him at 8:00 opening morning).
No picture with it loaded on my back, but here's the second trip with a front shoulder and a hindquarter loaded up in the pack after I emptied most everything out from inside. It carried well enough that I didn't bother with the external frame packs in the truck, just came back in with the Just one pack.
I packed out most of my friends Wyoming elk too and then started the pack out of my New Mexico elk.
The pack again could have handled this, but I couldn't and ended up hanging it up in a tree after about 1/2 mile. I was hiring some folks to go back in and carry the quarters out anyway so I had them bring the head out too.
Last pack out was my mule deer. I took him out in 2 trips and it was a breeze. I'm sure the pack could have handled him coming out in one trip, but I decided to take it easy. He was a pretty big bodied deer too, easily 250lbs on the hoof.
Hopefully I'll get a chance to figure out the best way to carry out elk antlers by doing it several more times over the next few years.
The pack is great, wears very comfortable. I tend to not keep the rifle in the scabbard during daylight hours when I have an unfilled tag in my pocket, but it works great for hiking into the woods in the dark to get where you want to be at first light.
I'm sure most of the other packs mentioned are great too. I won an Outdoorsmans pack recently and I can't decide if I want to sell it or keep it and use it.