I now have an HP LaserJet 2300 sitting on my desk. I think you could sucessfully kill one person with it without damaging the printer enough to make it stop working.
I've worked with a few 1000 series LaserJets, and I don't think you could kill a person with it without breaking the thing. Its just too flimsy.
You could kill a few people with a 4000 series, but I due to its weight you have to be rather skilled in handling it.
An 8000 series or larger printer could easily net you a massacre if you could arrange for a fire in the building such that you could push /drop it down a well-packed stairwell.
You may be wondering what this has to do with the quality of a printer. Well, I'll tell you. Printers vibrate and shake alot. They've got lots of complex little plastic parts. The more pages you run through the things, the more they vibrate and shake. So if a printer could keep working after being used in a blunt-force murder*, it must be good enough for your office.
No actual printers were harmed during the writing of this article.