The HP LaserJet Pro 400 Color M451nw color laser printer has nice output and is relatively speedy considering the price. However, it suffers from the same pricey toner of most entry-level colour laser printers, and it lacks the automatic duplexing found in HP's slightly more expensive 'dn' and 'dw' variants.
Our test M451nw was decently constructed. You can easily access the slide-out toner tray and paper path through a fold-down front panel. A pop-off panel on the right side makes it simple to upgrade the unit's standard 128MB of memory to 384MB. The one slightly bothersome component is the bottom-mounted, letter/legal standard paper tray. The tray itself is sturdy enough, but the latch holding it inside the printer offers barely any resistance. HP says it designed the tray to be easy to open, but instead the company managed to make it feel insecure.
The M451nw's controls are adequate for what is really a simple device. You get a two-way rocker button for navigating the two-line LED. That's fine for general operation, but not for manual Wi-Fi setup. You need to attach the printer via USB or ethernet to set up the wireless, unless your router offers WPS (Wi-Fi Protected Setup).
Paper-handling features are sufficient for a small office or workgroup, if the users aren't too far from the printer. Otherwise, this model's lack of an automatic duplexer will wear on those who must constantly run to the printer to reinsert documents for two-sided printing. The 250 sheet input tray, 50 sheet multipurpose tray and 150 sheet output tray are satisfactory given the unit's roughly 2000 sheet recommended monthly cycle. If not, a bottom-mounted 250 sheet auxiliary paper feeder is available.
Compared with similarly priced colour laser printers, the M451nw's per-page costs are decent. Next to business inkjet printers or inkjet MFPs in the same price range, however, they're exorbitant.
The standard black toner cartridge costs £66 and lasts 2200 pages, or 3 pence per page. The cyan, magenta and yellow cartridges cost £95 and last for 2600 pages, or 3.6 pence per page per colour. That makes a four-colour page cost 14.6 pence, a hair below the average for colour lasers.
A high-yield black cartridge available for £81 lasts for 4000 pages, reducing black costs to 2 pence per page. The cartridges that ship with the unit last approximately 1400 pages.
The text the M451nw produces is outstanding, dark and sharp. Colour photos are also quite good for a laser at this price point, though as with most HP printers, human faces have an orange cast. Our full-page photo showed a cool colour palette, and nice rendering of fine details.
The M451nw offers an economy mode to save toner. Output in this mode is legible, but only just. If you're going to spend any time perusing the document, or if it's for public consumption, you'll want to print at regular quality.
The HP LaserJet Pro 400 Color M451nw's lack of an automatic duplexer is an issue that you can overcome by opting for the M451dn (no Wi-Fi) or the M451dw (with Wi-Fi and, despite the absence of the letter n in the name, ethernet). Alas, neither of those models can solve the problem of high per-page costs. Consider a high-end business inkjet MFP instead, which could save you a bundle on supplies over time. Alternatives in this price range include the Dell 2150cdn and the Brother HL-4570CDW.