The price is right - below $500 Australian - and the form factor is excellent. To have a device that prints in good, clear colour, takes up no more space on your desk than the average b/w laser and also has the option of network connectivity certainly cannot be frowned on.
The printer is black and therefore has the added attraction of being somewhat good-looking. It comes with drivers for Windows, Mac OSX and Linux, which is a big plus.
It can print, scan and fax over the network and can also serve a a standalone fax machine or copier. One is restricted to just one size - A4 - but then that suffices for the average punter or small business owner.
But there are some aspects of the 3175FN that leave a bad taste in the mouth. One is the USB connectivity, which is nothing but flaky.
I've installed three of these printers recently and in not a single case would the USB connection work. I ended up using the network connectivity in every case.
There are reports on the internet that the USB works when the cable between the printer and the computer is not too long, but having tried with everything including a one-metre cable, I gave up. The addition of a powered USB hub did not help either.