4K Monitors for New Macbook Pro Retina 15"?

With the brand new 15" 2015 Macbook Pro Retina., will a 4K screen or screens be more efficient than using dual Apple Cinema 27" monitors?

(http://smile.amazon.com/product-reviews/B00PXYRMPE/ref=cm_cr_dp_srch?filterByKeyword=macbook&search-alias=community-reviews)

Seems that it’s time to get something new for a Mac screen:

Maybe this one:

From this answer to a question:

http://www.amazon.com/refresh-MacBook-support-3840x2160-displays/forum/Fx1AP2OV9BSB58N/Tx1BKJSL1MFY2SJ/1?encoding=UTF8&asin=B00DJ4BIKA&cdShowComment=Mx1VMEUDCZUJ7FZ&cdSort=oldest&ref=pe_623860_70668520#Mx1VMEUDCZUJ7FZ

Justin Gordon said on May 25, 2015  |  Edit 
Is the slow refresh annoying?
1Ronin said on May 26, 2015
Not at all. Buy the way that is a great price for the monitor, when I bought them last year they were 2400.00
Justin Gordon said on May 26, 2015  |  Edit 
@1Ronin, do you know if you can hook up two of these via miniDP? Did you compare to a Apple 27" cinema screen?
1Ronin said on May 26, 2015
There are two thunderbolt ports on the Mac. So in theory you should be able to drive two. I haven't tried. But that is an awful lot of pixels to drive. I wouldn't want to try much gaming. 

I have tried two apple displays and they perform very well.

But my favorite display to run off my Mac is an LG 34" 34UM95. Not 4k but very good resolution. They have a thunderbolt port, so you could drive 2. They are also on Amazon

Techbargains just posted about a Monoprice 28" 4k display for $399. Their shipping estimate claims to be free 2 day shipping to Hawaii (but I haven’t ordered from them before). I don’t know anything about the quality of the screen but seems like it could be a good deal.

http://www.techbargains.com/news_displayItem.cfm/453844

And the monoprice link: http://www.monoprice.com/Product?c_id=113&cp_id=11307&cs_id=1130703&p_id=12156&seq=1&format=2

Just picked up this one. $538 on AMZN prime! Woot! Woot! Very perfect colors. 30Hz is a bit annoying, but balanced out by sharper text. Comes with 4 USB ports. Neat! Nice stand. I’d say worth it!

Here’s some details on my setup:

Using a 2015 15" MBP Retina, maxed out, what’s the best source of information on ordering of thunderbolt devices relative to a cinema display? 4k screen, and 3 thunderbolt drives?

With the cinema display on the end, after the 3 thunderbolt drives, the sound is severely distorted.

I’ve never run the thunderbolt out the back of the cinema display.

And does the thunderbolt out the back of the cinema display power a 4K Display Port cable? (when I tried this on the back of the drives, I got only 2560 resolution, so I’m guessing that the 4k monitor needs a direct connection).

UPDATE
I’m quite happy with the setup pictured below:

  1. Cinema 27" on left
  2. Dell 2715Q 4K Running at next to highest resolution
  3. Retina 15" screen to right running at next to highest resolution
  4. Thunderbolt drives connected to Cinema 27", as well as USB2 and Ethernet
  5. USB3 drives connected to Dell 2715Q built-in USB hub.

Is there anything more optimal?

Is two 4K displays an option? Guessing not due to Thunderbolt.

Just in case anyone is interested in the Dell 34UM95 Justin has listed above, I now own one. I still am planning on getting a 4K, but I have to get a new laptop first. At that point, I am planning on possibly turning the Dell vertical to use it for console output and/or multiple browser windows at different widths when doing responsive web design.

Read this reviews of USB-C Monitors for MacBook Pro https://www.thecrazybuyers.com/best-usb-c-monitor-for-macbook-pro/