I'll have to defer to your experience with flashes and strobes. Perhaps because of our different styles of photography, we have different needs. But I can only speak from my experience, which is that I'm quite pleased with the EVF for what I doyes, a rhetorical question, I suppose. For someone who use strobes or flash extensively, EVF does not let see the exact representation of the image which will be produced by the camera.
Frankly, I'd feel a little lost with an OVF.