I'm prepping for a backpack hunt and looked into it a bit. I came up with the system doesn't seem to pack nearly as small or light as a decent down bag with an inflatable mattress so that did it for me. I'd be interested to hear from people who have tried it also
It's sweet, super comfortable. I use it with my sea to summit etherlite xt, zero issues. The lite quilt is down, so it packs just as good as any other down sleeping bag with 850 fill. Can't imagine going back to a mummy bag.