As you'd expect from an office-orientated laser printer, the Oki 321dn is suitably speedy. It printed our 20-page test document, which is monochrome and text only, in one minute and two seconds. Not a bad pace at all. Text print quality is also very good. We printed another test document that used two fonts and character sizes ranging from four to 18 points. The largest characters proved vivid and consistent, with no greying or bleeding in evidence at all. This is, of course, not surprising for a quality laser printer, but it's laudable all the same. At the lowest point sizes, text remains crisp, clear and readable, with no smudging or blurring.
Printing a two-page flyer using Duplex was simplicity itself, and the quality of the print-out was very good. Text was clear and solid, and images were well realised. Perhaps the colours were a little over-saturated, but overall detail was good on both sides of the paper – you didn't get the bleed-through suffered by some printers. If you regularly print documents that would benefit from using both sides of the page, the Oki C321dn is definitely worth considering.
As you might expect from a laser printer, its photo output failed to match its stellar text quality. Printing our PhotoDisc test image on standard, 75gsm photocopier paper at default image quality, the results left much to be desired. The print-out was over-dark, too red and the greyscale ramp looked banded. Ramping up the quality to its highest setting and printing on glossy photo paper improved matters, but it was still dull, lifeless and a little grainy. Skin tones were poor too. If you want to print a lot of high-quality photographs, you're still better off with an inkjet, especially a five- or six-tank Canon or HP Photosmart model.
Build quality is excellent. It's robust and well made throughout, so even in an office environment with multiple users, nothing's likely to break away or wear out. Our only question mark about the design and build is the second paper 'tray', which is a sheet feeder that opens at the front of the device. It's not as strong as the rest of the printer, and paper left in place is liable to get dusty if not used quickly. It's OK for light or occasional use, but not great if you need to regularly use two input trays. We appreciated the printer setting that let you use the sheet feeder for a document's first page and the main tray for subsequent sheets, though. If you need a letter-headed opening page but plain paper thereafter, this could come in very useful.
If you're planning to buy a laser printer for the home, be aware that this one isn't as feature-rich as we've come to expect from home inkjets. There's no Wi-Fi option, it's not AirPrint compatible and there's no companion app for smartphones.
The Oki C321dn is clearly built with small businesses and home offices in mind, or maybe for a manager's private office in a larger business. Its relatively small footprint means it will fit in most spaces, but it's not light – don't expect to mount it on a flimsy shelf. You can connect it to your computer using USB or to a network over Ethernet, though there's no Wi-Fi option. It's cheap to buy, costing not much more than £200, and running costs are reasonable.
Text quality is stellar, with crystal-clear characters even at low point sizes. It's very fast too, pumping out a 20-page test document in a little over a minute. We've few complaints about the build quality. It's certainly tough enough to take the knocks in a busy office, and it looks reasonably good too. Its 250-sheet paper tray is big enough for the small office, and it has some welcome features such as Duplex printing and the ability to print on the first page of a multi-page document from the secondary tray, and the rest of the document from the main one.
Although great in the home office or for small businesses, it's not so good for in the home. It lacks significant features we've come to expect from home printers, such as Wi-Fi connectivity, mobile printing options and smartphone support apps.
Its photo output leaves a lot to be desired too, with over-dark, grainy prints that are nowhere near as good as even a cheap inkjet. To be fair, it's not designed for the all-round home-use market, though it's worth pointing out that if you're looking for a laser-based replacement for your trusty home inkjet, this might not be the ideal printer for you.
Is the Oki C321dn worth buying? Yes, if you intend to use it in the role for which it was designed, a small office or home office environment, or maybe as a manager's private printer in a bigger business. If you want a fast, cheap laser printer that offers excellent text reproduction and a meaty paper tray, you could do a lot worse than this.
If you need to keep letterheads, envelopes or other such non-standard papers in place on a semi-permanent basis, you might be better off with a model that has a second paper tray instead of a sheet feeder. Like most affordable laser printers, the Oki C321dn is not good at printing photographs. If this is important to you, you're better off with an inkjet.