Phil,
thanks for your comments - that was EXACTLY what I need to know to overcome my doubts about fiber optics with the E-M5. You own both cameras, so you KNOW what you are talking about. Yes, yes, focus time with the RS - do/did you use the 2x converter? THAT thing makes the camera really slow... Once tried to take a photo of two mating nudibranchs. By the time the RS had found the focus I shot the puppies!
And of course you are right - the more powerful the external strobe, the quicker the recycle time of the internal strobe. Unfortunately, my trusty old Ikelite SS200 will not work with fiber optics (or is there a converter? If so, they might be useful for wide angle, where I shoot manual strobe anyhow.)
@ guyharrisonphoto:
For me the question was if there is a way to hard-wire the E-M5 for TTL shooting. If you decide to shoot manual, then i would definitively NOT hard-wire the strobe(s), because, as Phil stated, a TTL cable is one more option for failure...
Maybe Alex' suggestion is the way to go: A light cannon!
Jock