so, what is ghosts?
at the time, people were comparing it to the tail end of the aphex twin's career, even though reznor had been playing with the style for over a decade. it was a reflection of a deficit of context.
what reznor did with ghosts is kind of sneaky, as he would have released it with the title etudes in a previous era. and, i think that in order to understand what ghosts is you need to go to look into the genre itself, perhaps beginning with debussy's livres.
when you put it into this correct context, ghosts actually becomes an academic exploration of his composition style. reznor has a kind of idiosyncratic approach to tonality, defined by a highly minimalistic approach to dissonance. so, he uses a lot of pedal tones, and then sprinkles "wrong notes" over them in predictably calculated ways. that's the crux of his style, stated in easy to understand terms.
when understood this way, you can actually identify ghosts as somewhat of a pivot in his career. broadly speaking, these are not new themes. but, the disc defines the approach he's taken to soundtrack music, since.
if year zero was both a comeback and a coming-back-down-to-earth, ghosts was the logical conclusion of that process, in charting a new direction for his creative output. and, while i haven't followed this new direction as closely as i followed the previous one, or at least haven't up to this point, it is certainly a turn towards the tasteful that is worth respecting.