I was in the B&H mega store in NY the other day, and had a chance to look through several EVF.
No, I seriously mean HOLY FREAKING CRAP!
They should come with a Surgeon General warning! If I suffered from seziours, I would have certainly got one on the spot. All that flicker, jittery movement, frozen movement when shutter half depressed...
The worst was Fuji XE-1. The best (but still eons away from OVF) was the new Olympus. I guess the only way to find them remotely acceptable is to be born after the digital revolution.
I don't know about Sony or Fuji, but have the OMD and Gh3 with evf.
The OMD, you have to learn the menu and that's not an easy task with 86 something menu options, or more, who knows?
But once done you'll find a big difference. The GH3 is almost perfect, out of the box and it will take you a while to realize it's not an EVF, except for the fact that WYSIWYG if you so desire.
You can set both to work semi like ovf for strobe work or if you want to see in virtual darkness.
I'm not selling you on an EVF but you can't walk into a store, spend a few minutes and understand without knowing the settings.
I personally like them, especially for manual focus because you can see what's in focus unlike a modern dslr and you can even set a zoom factor so it briefly zooms in on the subject and then backs away to full screen.
Some people find this limiting, though I think EVF are no more limiting than optical finders. Optical finders in dslrs virtualy can not be focueed manually on moving subjects, suffer from flare, and require most people in set up to shoot a frame, move their head down, hit a button view the image, make an adjustment then spin and repeat.
EVF let you shoot and see exactly what your shooting, never move your eye from the viewfinder adjust exposure and shoot again.
All cameras are different, all have different plus and minuses but next time, give it a moment, set up a menu and try it then.