I purchased the LaserJet Pro M426fdw about one month ago. I strongly recommend the M426fdw if you do not need color printing (nevertheless, the M426 can scan/capture color documents and images as full-color images). Fast duplex/two-sided printing and the scanning speed is pretty good. The response of the touch-screen is okay but the screen is somewhat small and can be annoying when I have to tap 3-4 times to select one of several closely positioned option buttons. Same issue with the keyboard for entering text on the "Subject" line of a scanned document... I often have to correct for mistyped text because the keyboard keys are small and a key adjacent to the one I intended is activated. Probably best to use a rubber-tipped stylus for the touch-screen.
I purchased the M426fdw after first purchasing and then returning the M477fnw. I'd purchased the M477fnw thinking it supported duplex printing and realized after I'd set it up that it did not. I'd compared the specifications listed for the three M477 models provided at the HP website, but the comparison does not exclude the features that are identical for all three, and sometimes the descriptions for the same feature are worded differently for each, which can be confusing. Apparently I misunderstood what was described for duplex printing versus duplex scanning and selected the wrong M477 model, thinking that the fnw had duplex printing as well as duplex scanning. I should have ordered the M477fdw. Manual two-sided printing would have been okay if I could have fed the page through the multipurpose feeder/tray to print the second side. However, neither the HP user manual, the YouTube video about duplex printing, nor the live customer support explained how to accomplish that with the MacOS printer driver/print command interface. Also the M477 color laser jet printer does not allow true monochrome (B/W) only printing, at least not with the MacOS driver. It's either color or gray-scale printing and gray-scale uses a mix of color toners as well as black toner.