Mystic River has a pretty good rep.
The other gold standard in packs is Kifaru. I used the Kifaru Pointman for 7 months in Afghanistan, both mounted and dismounted, and it fits all your criteria (including the armour part).
https://kifaru.net/pointman.html
I put a long pocket in each side. The top of the ruck contained my sleeping gear while the bottom had clothing, spare water, and some other stuff. The top and bottom access made it pretty easy to get at stuff without having to pull everything out. One side pocket had 72 hours rations while the other side had mission essential stuff (radio batts, 7.62 link, spare smoke) It was heavy, but it was as good as a backpack got.
The downside is the steep pricetag, but you get what you paid for.