I've tended to avoid public trackers when I can find what I want on private ones. I'm not sure that they are any safer in terms of consequences resulting from being noticed by media firms and relevant legal groups, but the transfer speeds are generally better (due to there being less leeching presumably), and public tracker UIs tend to be more filled with junk that sometimes gets past my ad/malware filters.
[Not a comment on Audiobookbay specifically, I don't remember having tried that one and it may be great for all I know]
