Qrbert - the five min T-13 rift is more about the monster density, If you get a crowded rift it's real easy.
So it would seem! I had a rift in Briarthorn Cemetary, wall-to-wall Elites, wearing Nemesis Bracers and all my equipment tuned for Damage over Toughness, and I was getting used to
not picking things up, even Shineys. I did pick up a few, when they happened to drop right where I was going to click to move anyway, but apparently I still finished in time because I visited Orek and got the Achievement and notification. Finally!
Then I snapped out of my daze and ran back into the rift to see how much I could pick up in the seconds that remained. Piles of Death's Breaths, a couple more Shineys, and just as 2 seconds remained, I clicked on a Resplendent Chest. I heard "Zinggg!" as an orange star appeared on my mini-map, then I was suddenly back in town. Damn! I'll never know what it was. That's what bugs me the most, not knowing.
Oh well, Nicole the Witch Doctor is now a Conqueror.