Edit. I also forgot to say using a reference price on monitors is a tricky game. http://www.stltoday.com/business/lo...cle_41090317-811c-5c94-ac9c-a17889c34a41.html
The ability to fit output, IM with the client, debug and the original document/coding window all on one screen at once is something I could probably make use of. 2160 vertical pixels (assuming landscape) is something of an improvement over even 1200 or 1440 of the previous higher end displays, I know 1600 exists but that was quite rare and the others are available from most vendors that matter.
But is it something to buy a new screen for? TBH, when I am using a lot of different programs, and thus have a lot of different windows, I highly prefer multiple monitors. My current set-up at my PC (22" - 16:9 - 1080p and a 17" - 4:3 - 1024p) is more than enough for me. I use my main screen (22") for gaming and video's, and my second screen (17") for information regarding the game I'm currently playing (self-updating MC map when playing multiplayer, or guides and stuff like that). A friend of mine, who sometimes stream, uses my second screen for the twitch page. Having bigger screens would be worse for me.
And I know that most people have to go bigger to see the advantage. I tested a lot of configurations with all my devices; 32" 1080p TV, 22" 1080p monitor, 17" 1024p monitor, 17,3" 1600x900 laptop screen and a 10.1" tablet. So far for 'normal gaming' the 22" and 17" screen are the best, with the 10.1" tablet for mail and other notifications that are sent to my phone and tablet. When I want to play games on my TV, I use my laptop and set the tv up as a second screen, so it doesn't copy the screen.
One thing I can't wait to test out, are the new 'curved' displays. I've heard a lot of good stuff about it, and can't wait to see it myself.