Canon claims 20ppm as a top speed for this multi-function and although we didn't reach that in our tests, we did get our five-page text file out in 25 seconds and the text and graphics test in 27 seconds. This gives a top, real-world speed of 12ppm, not at all bad. The duplex speed is also quick, with a 20-side duplex document completing in 1 minute 54 seconds, or 10.5ppm only a little slower than the top speed for a single-sided print. A best-quality 15 x 10cm photo took just 10 seconds.
Text print comes through well, with clean character edges and very little spatter. Even small text sizes look very crisp on both single-sided and duplex documents. Greyscale tints also look good and text over grey tones is well registered.
A photo print, using the driver's photo settings, also shows good levels of detail in both high and low-light areas of the print. There are some slight gradations in areas of varying tint, but generally photo reproduction is fine for a mono laser.
The only printing which was below par was when we photocopied originals containing greyscale tones. Whether from the glass or the ADF, these were reproduced very patchily, though text and solid lines came through well.
Unusually, while Canon claims a noise level of 66dBA maximum, we saw nothing above 60dBA and all of it as subjectively unobtrusive hums.
There's only one consumable for the i-SENSYS MF4270, so working out printing costs is very straightforward. We get an ISO page cost of 1.65p, which is at the low end of the range for mono lasers. That doesn't mean we wouldn't like to see a higher-capacity print cartridge, though, good for, say, twice as many pages.
This is more because of the amount of maintenance and waste recycling that has to go on with a 2,000 page consumable. A print cartridge is a complex mechanism, so manufacturing one has a high energy cost and the fewer made the better. If one can be made to last twice as long by filling it up more, it helps save money and the planet.
Just out of interest, compare this machine with the Sharp AR-M201F, reviewed last week. This Canon multi-function is consistently faster when printing real-world jobs, has a similar feature set, has no warm-up time from sleep mode and takes up much less room on your desk. It's not as expandable as the Sharp and page costs are higher, but you can print an awful lot of pages before the Sharp equals it on overall cost of ownership. The Canon i-SENSYS MF4270 is less than a tenth of the cost of the Sharp and is very good value in a SOHO or SME environment.