I think that if you have a good grasp of the commands in an editor such as vim, having "real-time" feedback isn't as important as with other UI paradigms (as long as it's not too slow, you do need a few fps). Though I'm not sure. It will take some getting used to. The nice thing about E-ink is that looking a the screen is very relaxed, as it doesn't emit light. I'd love to buy an E-ink monitor to try out, when they are available and affordable enough.