I've had one of these printers for nearly a year and have been very happy with it. Recently my older HP 970 finally quit with no obvious way to fix it, so I bought another 6988. In my opinion, this is one of the handiest printers to have in your house if you have wireless local area network. It has wireless integrated into the printer and it is a snap to set-up. You can put a printer wherever it's convenient without worrying about cabling it to your computer.
I recommend the two-sided accessory if you print many multi-page documents and want to make the result thinner. I used it for the Club auction catalog for instance. Duplexer costs about $38 from HP.

This printer design is a year or two old now, and new printers are available everywhere for from $70-90. Mine cost about $95, shipped. In fact they are so cheap, if found that you can get a new printer with ink cartridges for about the cost of a pair of new cartridges (B/W and color). I may just buy several more printers to keep around for parts and use the ink for my current printers [g].

If you are a higher volume user, you might also like the accessory paper tray that lets you have about 3x the paper capacity (another $38 from HP).