The speed of optical vs. Radio has much more to do with delays and latencies in camera and flash electronic systems than the type of waves traveling between the systems. EM waves are so fast as to have no effect at typical photography exposure times. To know the speed differences of any system you have to know the electronic specs of each, radio or optical. I doubt the detals of such are published by most manufacturers, but they would know best (if you can get them to devulge ).

The speed of optical versus radio has much more to do with delays and latencies in camera and flash electronic systems, than the type of waves traveling between the systems. 

EM waves are so fast as to have no effect at typical photography exposure times. To know the speed differences of any system you have to know the electronic specs of each, radio or optical. I doubt the details of such are published by most manufacturers, but they would know best if you can get them to divulge.