Summary: My company buys these as report printers for criminal applications. Very reliable and cheap to replace. I bought this printer for my home almost three years ago and it is still working great. It is easy to connect via the IP address and it just works. I paid $124 with $25 instant rebate. On my second full cartridge. Will definitely buy another if this ever fails.
Summary: For the four days I've owned this printer, it has done a great job printing for my home wireless network. This printer set up relatively easily for me; I connected it via cable to my wireless router (had to buy the router-connection cable separately). Once connected, the printer spat our a test page that included an IP address for the printer. Then I downloaded drivers for Vista 64-bit and XP, since I have two laptops.
Summary: I do a lot of work on pre-printed forms (single sheet, normal weight paper). This printer constantly pulled in the paper incorrectly and thereby printed crookedly on the paper. My inkjet worked fine on the forms, but I need the greater permanence of the laser print. I worked with Lexmark customer service and they were kind enough to replace my first 120n, but the replacement was actually worse.
Summary: Let's start with the problems. After two cartridges failed in less than 400 pages total, I'm returning the printer. The documentation is terrible. Just try setting a static IP address on the thing! I had to call technical support a few times to get correct and complete instructions. Which brings be to the third problem. Their tech support sucks. Their hours are limited and their people are not too bright. Expect to get about 500 pages out of the original cartridge.
Summary: An amazing printer for the money. I am in charge of technology in a high school and I have several of these printers in small offices with 5 - 10 users per printer. Easily networked and great for low to medium volume printing. They have held up so well I bought one for my home network and at under $150 it is a bargain.
Summary: For SOHO (small office/home office) users looking for an inexpensive, small, quality black and white laser printer, the E120N is probably the best on the market. This unit is provides high quality, fast output, Ethernet networking, efficient use of toner and a small, well designed profile that allows it to fit well even in tight spaces of small offices.
Summary: I upgraded from a USB color inkjet to this networked laser printer. I can't believe how fast the printing is and I can't believe the convenience of having the printer on the net. I'm technical enough that I was able to give the printer a permanent IP address and all the computers at home (about 6 of them) have no trouble finding the printer using Apple's Bonjour or avahi for Linux. Other reviewers complain about tech support but luckily I haven't needed it.