Is this different (in function) than
SqueeBook?
http://www.squeebook.net/
I've used to convert LiveJournal posts (story over many posts) into ebook format. SqueeBook does not grab the comments either.
PS: I haven't tried Readlists yet. May try it out....but I tend not to use the automated ebook makers in the end as its still sloppy formatting. I code by hand...yes I'm a code snob.
As for being piracy. I only do this for my own consumption, it's posted publicly, for free, so I do not consider this piracy. If I want to share my ebook version of a fic I ask the author if they are ok with it being in this format (and give them the ebook to review). If they are not it doesn't leave my hands...but I do like having it on my mobile device for reading when away from a internet connection.