iMac: 5k or non-5k for video editing?

Im in the market for a new mac for video editing my GH4 4k files (FCPx and Davinci for grading) and I've decided on the new iMac. However, I'm trying to decide whether or not the 5k is worth the extra money. My eye sight isn't good enough to appreciate 5k anyway (lol) so Im just not sure if it's worth spending extra on it if I can get the same specs with a normal screen for less.

Does anyone have an argument to support or counter the decision to buy the 5k iMac?

Is the 5k iMac right for you? Who knows. What I do know is that everyone I know who sees the display for the first time is blown away - it is like nothing you've ever experienced in your computing history. No RAM/CPU/GPU/performance upgrade you've ever experienced with a computer can touch that 5k display. It's otherworldly.

[Peter Chamberlain]

We recommend the Retina with top of the line GPU, not the alternatives.