It isn't as flashy like Apple's Retina display-equipped iMacs, but the standard 21.5-inch iMac is as stylish and convenient as ever.
It features Apple's renowned build quality, runs a vast selection of OS X apps and is just as compact as the 4K Retina iMac - so you get the qualities of a more expensive computer for a lower cost.
Apple's 21.5-inch iMac is the cheapest iMac, and a convenient computer to boot. If you're looking to banish the complexities of Windows machines and like the iMac's slick design, excellent build quality and bright (but not particularly sharp) display, the standard 21.5-inch iMac is a great choice.
With surprisingly good speakers, a healthy selection of (annoying located) ports and enough power to handle every day tasks, you can't go far wrong. Just make sure to upgrade the standard spinning hard drive to a Fusion Drive to avoid slow boot and app loading times.
The 4K iMac exists for a reason, and you should consider that model if you aren't prepared to put up with jagged fonts, pixellated images and everything else that comes with stretching 1080p across a 21.5-inch display.
The 21.5-inch iMac's 1080p display is not unpleasant to look at, but its lack of clarity isn't as pleasing on the eyes. Having fewer pixels also makes working with spreadsheets and large websites that bit more difficult.
As with other Apple computers, the 21.5-inch iMac lacks height adjustment, and reaching around the back of the display to connect peripherals can become a chore when you're doing it daily.
It feels like the standard 21.5-inch iMac still has a place in the world. Not everybody needs a high-resolution display, and the cost savings that can be made by opting for the non-Retina model can be either go straight to your pocket or be put toward boosting the iMac's configuration.
You should swap out the spinning hard drive for a Fusion Drive at the very least, if only to avoid frustrating boot times and to wake the machine from sleep faster.