My controllers sit on charging cradles all day so I (personally) don't have much of a need to know current battery status. I have young boys who love to put their controllers down to go to get a drink or go to the bathroom (or something) and come back and say "which controller is mine?". If the LED displayed the P# I won't have to truck upstairs to solve their mini mystery.
Certainly a low priority request but, thoughts?
John