I've owned an HP 6210 for 4 months now and 3 months of that time has been spent repairing the unit.At first the unit worked great (even flawlwssly.) But then the problems set in. I'd used nothing but genuine HP cartridges and excellent quality paper but the machine began constantly failing alignment, misaligning the printing, jamming, rolling out several pages at once, and fighting us on printing any document. Perhaps I bought it too soon (they'd just hit the streets in November '04) and the bugs weren't worked out yet. I have a small business that prints just a few pages a day and it fails even that basic task.
I've contacted hp support and for the first 2 months they told me that it was a print head issue and that it had to be cleaned specially. Ok. They gave me the directions and I pulled out my q-tips and distilled water and went to work. (I'm a bit of a computer tech so this wasn't all that difficult for me, but the process takes an hour.) After extensive cleaning (which burns a lot of ink out of the cartridges) it worked for a few days but would go right back to misprinting. I did it a few more times but eventually it just began failing permanently.
I contacted hp support again and they finally agreed to send us a new unit which we are currently awaiting. I'm hoping I just got a bad apple but Im not holding my breath. I suggest looking elsewhere. Good luck.