The following compares the current state of Shadow Priests to Windwalker Monks using the latest SimulationCraft data for end-game PvE in World of Warcraft The War Within patch 11.0.2.
Comparison
Category
Winner
Windwalker Monk
+11.9%
When simulating boss fight encounters, Windwalker Monks averaged 11.9% more DPS than Shadow Priests (+190K DPS).
Windwalker Monk
+12.5%
When simulating AoE DPS, Windwalker Monks averaged 12.5% more DPS than Shadow Priests (+124K DPS).
Windwalker Monk
+43.42%
Windwalker Monks have higher spike damage potential, achieving +3.8M more DPS than Shadow Priests.
Spike damage is the peak DPS achieved in any given moment and is not sustained DPS.
Windwalker Monk
+1.44%
When upgrading the gear for both specs by +44 ilvl, Windwalker Monk DPS improved the most, +1.44% more than Shadow Priest. In total, Windwalker Monks DPS increased by 68.31% and Shadow Priests by 66.87%.
Windwalker Monk
+0.65%
+ Movement and latency lowered the DPS by 8.19% for Windwalker Monks.
+ Movement and latency lowered the DPS by 8.84% for Shadow Priests.
When introducing occasional movement and real-world latency, Windwalker Monks performed better, as Shadow Priests suffered a +0.65% DPS loss.
Shadow Priest
When evaluating abilities used during boss encounters, Shadow Priests 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 Windwalker Monk in the current meta, which can hopefully help you determine which spec to play or group up with.