It features 3 buttons, and when they work, they make this scanner a real pleasure to use. Just press the button, and your printer instantly starts printing what you just scanned. The other buttons are for normal scanning and making small JPEG's to send via e-mail. The 4200c is light and flimsy. My first arrived broken, in fact.
Scans are fair at best, but OK for most home scanning.
The bundled Precision Scan Lite software is nifty and quite useable, although not as flexible as I would like. Now, the bad. The software and drivers for this scanner are good when they work, but they seldom work. Installation often fails. Updates from the HP site help little, and HP tech support is the worst I have ever seen.