It actually came up way back in the Thrawn Trilogy, where Admiral Pellaeon notes that serving under Vader was considered a fast track to promotions due to him constantly killing off officers who failed him and moving others up the ranks as replacements, but was also a double edged sword because, well, he constantly killed off officers who failed him. It also meant a lot of the Empire's best and brightest were killed when the Executor went down and contributed to the Imperial Fleet's downfall.