We've looked at the late-2012 27in iMac before, but this is a prime example of how selecting exactly the right configuration can make such a big difference to price and performance. See also: Group test: what's the best all-in-one PC?
To recap: the iMac is a design masterpiece with build quality second to none and looks which will impress in any location. The display quality is superb. Used by the most demanding professional photographers and designers the world over, its 2560 x 1440 IPS panel delivers outstanding image quality with great contrast, accurate colour and huge amounts of brightness in reserve.
Colour reproduction is excellent, offering a slightly wider range of colours to ensure that full range of sRGB colours is covered, with a little in reserve to ensure that this 100% coverage is maintained as the monitor ages. Only the Adobe RGB display of Dell's XPS 2720 was able to challenge this.
This review model incorporates a high-level specification, but steers clear of the very high-end options found in the built-to-order version we tested last time. For £1699 you get a 3.2GHz Intel Core i5-3470 quad-core processor, 8GB of memory and 1TB hard drive. Graphics are provided by an nVidia GeForce GTX 675MX chip with 1GB of VRAM.
This is a step down from the Core i7, Fusion drive and GeForce GTX 680MX of the fully-specced model, but saves you a whopping £480 while still delivering superb performance. This less-powerful graphics chip still outguns the best of the competition by at least two to one.
Core system performance is very good. Its PCMark 7 score of 4141 points was ahead of most of the competition, but both Chillblast and Dell manage significantly higher scores thanks to their use of solid-state drives and faster processors.
However, the iMac's class-leading graphics performance is useful not only for gaming, but for speeding up exactly the kind of applications many Mac users love – such as Adobe Photoshop and Lightroom, both of which use the graphics processor to speed up operations.
If funds won't stretch to this high-end model, you can cut back on the CPU and GPU and still have a 27in iMac for £1499. The iMac is no longer fitted with an internal optical drive, so you may need to find an external USB drive.