The Automatic Document Feeder takes more than one sheet at a time when scanning. I found the same defect with 3 4101fdws I purchased and replaced over the course of a few weeks.
Print quality was terrible, splotches everywhere. Had to se for heavy paper to avoid the splotches, which added to print time. Didn't have 2 weeks and had to send back as document feeder malfunctioned and wouldn't reset.
There are now two professional lines, this one ends in "e" and is not able to network well. I was told in a chat to purchase a USB cable to connect, but the "e" version cannot connect with a USB cable, and has alot of network set up to make it work. The website needs far more information telling the difference between the "e" versions and the non "e" versions.
Not happy with this new printer/scanner. The sleep function hangs the printer up. It shows up as offline to workstations and we have to unplug the printer to reset it since the power button does not turn the machine off. Paying IT consultant to troubleshoot with HP as I write this.