I think both have their advantages and disadvantages. I like reading long chapters, but waiting a whole month is a bit annoying since I'm kind of impatient when it comes to reading. >__< That's why I prefer shorter chapters and faster updates.

But I guess both is fine as long as the story isn't abandoned suddenly... I remember a few amazing fanfics I followed years ago that were left unfinished. T__T

i seem to share the sentiment as the other commenter here to an extent. as long as they update lol....honestly i myself am guilty for always leaving my fics abandoned saved for a few times when i manage to sustain the momentum till the end without losing inspiration first... and most of the fics i subscribed to now haven't updated since forever too...but oh well, i subscribe to stories i really like so i'd rather take an un-updated story i like than one i find mediocre but update fast/consistently...i know short updates can feel inadequate...but to be able to do short but impactful update is a skill in itself. but if longer wait is needed for a quality update, i wouldn't oppose to it either. in the end, it's the story that matters.

I think it really depends on my time and the given situation. I'm really busy and would prefer a story that is under 3k words so I can quickly read in on my phone before I head to university, or while I'm on the way home back on the bus. In that way, I have time to drop a comment as well.
If I'm hooked into a story, I don't mind whenever the author updates, as long as they don't leave me hanging for years (I'm also guilty of this as an author too!)