Some are, some aren't
Power users are just like ordinary users. Some know what they're doing - others don't have a clue. The biggest difference is that they all take a disproportionate amount of support resources to stop them moaning like little babies when they run into difficulties.
Of our "power users", some genuinely have the ability to save the world - or at least earn the company enough to justify the huge bonuses the directors get. Others are basically just drama queens (of either gender) and create more noise and uncertainty than anything else. The hard part is being able to distinguish the one from the other.
Of course, the really valuable employees are the invisible ones. The ones who quietly get on with their jobs: competently, on time, solving their own problems as they go and doing what they said they would. However their lack of "star quality" usually gets mistaken for idleness and as a consequence, they're the ones who get axed at the first signs of economic trouble.