I'll answer my title question:
I am not a fan of prologues. Most of the time in a book I jump past them into the meat of the story.
The reason I don't like them is because (again, this is my opinion) so many of them seem like an information dump of background that the author isn't sure how to convey later on, or worse yet, a synopsis in hopes of hooking the reader that they really will like the story. (keep in mind, this is my opinion of prologues. )
I love to get all the background exposition fed to me slowly, so I can savor the information. So I can have those "ah HA!" moments. Especially if it's fed in small, teasing doses that make you eager to experience more of the story.
I don't need to know who's who and what's what from the beginning. I like to find it out later as the story unfolds like a ranunculus opening to the sun.
Again, though, it depends on the prologue writer and how much they tell as opposed to show.
What are your feelings about why you like them or don't?
I know for a long time they were considered far too old-fashioned but like the saying goes, "everything old is new again" so I'm thinking that might be the case now.
Write hard, write true.