I'm a DK, most of my guild overgeard me by at least 10 ilvl and i'm always last man standing, So yeah let me be a bit sceptic about tank cloak.
It nice against MASSIVE amount of single attack damage(non talking about horridon's melees), but hey! ain't DK shines on taking massive singular attacks due our HP and Will of Necropolis proc? non talking about OP Purgatory+VB+Ghoul Sack while over kill blows occurs.
This cape is a must for low HP tanks AKA almost all ESPECIALLY those pesky DPS minded brew monks that wiping on heavy magical damage fights "because crit is better".