Having used one, I can say that changeable photo displays with LCDs, OLED, or anything emitting light is a non-starter. It lights up the whole room (think about what happens when you turn off the lights!) and just doesn't feel at all like you're looking at a printed out photo.

I haven't seen a color e-ink display in person so I can't speak confidently, but the demo videos don't look washed out to me.