Although I have been through several computers during the life of my Samsung 24 in monitor I never saw a reason to replace it since it had a resolution of 1920×1200, a bit more than the 1080p monitors that have flooded the market. I had purchased that monitor in 2007 for a price of $399 and until recently it worked faithfully. Then it would no longer turn on so I needed a new monitor to work with my MacBook Pro Retina computer.
I wanted something larger, at least 27 in. I considered the Apple Thunderbolt display with a resolution of 2560-by-1440, but the high price of $999 and the fact that Apple has failed to update this product it in a few years was a big negative. The 1080p monitors, especially at 27 in, seemed to be too low of a resolution. I though about one of the 27 in, 2560×1440 monitors but they were mostly in the $500 range, or more, and lacked the full 4K resolution my Macbook Pro could drive and at a resolution of 3840×2160, which happens to be twice the pixels in each direction of a 1080p, for a total of 4 times the number of pixels.
I ended up buying the 28 in Samsung 4K monitor for a price of $489.
Even at 28 inches, I need to use the feature in Mac OSX Yosemite, to scale things for the monitor. Open System Preferences and then select Display. If you change the resolution from the default to “Scaled” you see five options, each showing larger text. I picked the center one so things “look like” they would be on a 2860 x 1440. However I am still getting the full 4K resolution, and just like a Retina display on my MacBook Pro display, the text is scaled so it is not tiny, but you get much sharper text than on a lower resolution display.
This Samsung monitor does not have a IPS screen so it might not be the best choice for professional photography work since with a TN display, you do get some color shifting if you look at the display off center. I have found that the wide gamut of 1 billion colors does make it look much better than other TN displays and it works find for me for photography work. After I calibrated it using only the built in tools in OSX, it looks very similar in color to my Macbook Pro retina display. It really shines for web development, with a combination of more real estate and sharper text.
Some complain about the lack of being able to us a VESA mount but using it on the include stand works fine for me since I have a deep corner section on my workspace, although the stand could be beefed up a bit.
You can use a HDMI cable to connect to the MacBook Pro Retinia, but you will only get 30Hz, so is much better to buy a mini display-port to display port cable, which will then drive the monitor at 60Hz refresh rate.