I believe the screens only show an ETA when a bus is en route; otherwise they display "Every 20 minutes".I like the resort boards and our experiences with them have been pretty good.
The frustration is exiting parks... but more often than not, that too has been ok considering the amt of people being moved. It seems certain resorts are always longer lines... Por comes to mind.. ( we jump on pofq and walk it)
I think people would like the boards...
I know I would