I have a 27" HPZR2740w 1440p connected via a
mini DisplayPort to DisplayPort cable with no issues. I also have a 27" LED Apple Cinema Display 1440p.
The HP and Apple screens behave and color very similar except the Apple is glossy. Basically you could get two ($449 each) for less than the price of one Apple.
http://www.bhphotovideo.com/c/produ...d_XW476A8_ABA_ZR2740W_27inch_LED_Backlit.html
EDIT: The market has fallen out on 1440p monitors with the coming 4k monitors. It's a good time to buy. There is nothing special about the Apple TBD. It looks nice. It has thunderbolt. After that it's just an LG panel and frankly, not worth $999. It's IPS, the color is ok. the speakers are handy. But it is 8-bit and bands and only has a prosumer color space. You can def do better for the money. I have two of these HP monitors on my PC as well, so, I own 3 of them and have been happy with them given their limitations. I have no delusions that they are Dreamcolor 10 bits or super accurate Eizo or NEC. They are pretty good though. The Dell monitors are also good. I've only heard some complaints about a sparkling anti-glare, but I'm not sure which monitor had that and I heard they revised it at some point anyhow.
I calibrated both my Apple Cinema and my HP and they looked very similar before, and very similar after. Neither needed a whole lot of calibration, just got some of that blue out mostly.