There appears to be a common spec page for both. I'm guessing the only
difference may be included software or packaging. It may be similar to the
old Xi/Se naming they used to use. SE's were general retail, and Xi were
for warehouse and other 'low cost' places. Mechanically/Electrically, they
were identical.
HP printers with the w after the number are for Costco(maybe other discount
places also). There is no difference, except they are usually 10 to 15
percent cheaper.