Huh?The benefit ought to be more than the loss for the PRSU gearing.
Can you give an example explaining this, with equations?
So, you are saying that a motor "optimized" to run at, for example, 3000 RPM, going through a PSRU to turn a prop at, for example, 2000 RPM is more efficient than a motor "optimized" to run directly at 2000 RPM???? And weighs less (motor and PSRU)? And is more reliable? (Remember Pops signature: If its not there, it cost nothing, weighs nothing, and is 100% reliable.)