The following compares the current state of Shadow Priests to Unholy Death Knights using the latest SimulationCraft data for end-game PvE in World of Warcraft The War Within patch 11.0.2.
Comparison
Category
Winner
Unholy Death Knight
+9.13%
When simulating boss fight encounters, Unholy Death Knights averaged 9.13% more DPS than Shadow Priests (+141K DPS).
Unholy Death Knight
+8.49%
When simulating AoE DPS, Unholy Death Knights averaged 8.49% more DPS than Shadow Priests (+80K DPS).
Unholy Death Knight
+16.57%
Unholy Death Knights have higher spike damage potential, achieving +977.6K more DPS than Shadow Priests.
Spike damage is the peak DPS achieved in any given moment and is not sustained DPS.
Shadow Priest
+1.9%
When upgrading the gear for both specs by +44 ilvl, Shadow Priest DPS improved the most, +1.9% more than Unholy Death Knight. In total, Shadow Priests DPS increased by 66.87% and Unholy Death Knights by 64.97%.
Unholy Death Knight
+2.04%
+ Movement and latency lowered the DPS by 6.15% for Unholy Death Knights.
+ Movement and latency lowered the DPS by 8.19% for Shadow Priests.
When introducing occasional movement and real-world latency, Unholy Death Knights performed better, as Shadow Priests suffered a +2.04% DPS loss.
Unholy Death Knight
When evaluating abilities used during boss encounters, Unholy Death Knights had fewer damaging abilities in total, indicating a potentially less complex rotation.
The comparisons above highlight some of the key differences between Shadow Priest and Unholy Death Knight in the current meta, which can hopefully help you determine which spec to play or group up with.
Unholy Death Knight
Shadow Priest