Story, story, story. That is the tyrant of the work, IMO.
If it (whatever "it" is) does not serve the story, get rid of it. If it serves the story, keep it.
Is a prologue an active participant in moving the story? In my experience, it never is. It's the author providing something he or she believes the reader needs, but it does not, of itself, get the story moving. It could be fantastically written, but if it's this sort of "thing" attached to the front end of the work, and not the story itself, it should be gone.
If that prologue moves the story, gets it running, then I don't think it's a prologue at all. It's chapter one. Or part of chapter one.
I'm a radical anti-prologue advocate. I feel that if a story needs this discrete piece or bit, then the story is flawed and should be retold. Or the author isn't giving readers credit for wanting to discover their world as the story takes them through that world.
No, Twick mentions something very important. "The first chapter starts off slow." Is that slow part fixed by tacking more information in front of it, or is that section still slow?
IMO, a prologue doesn't fix a story, or fix the writing. If you're using a prologue to try to fix that other part of your story, you've failed before you even got started on the prologue. Slow doesn't become fast because you have an extra one, or five, or ten pages in front of it.
I don't feel that I have the right to tell one author in one work whether the prologue belongs there or not. But if you tell me it's a prologue, my first question is, "where does your story begin?" I'll follow right up with, "how does this serve to begin your story?"
What EXACTLY are you attempting to accomplish? Does it serve the story? I have my radical opinion of it. Be ready to answer some tough questions.
And remember, writing might be an art, but publishing is a business. How prepared are you to limit your options for that prologue? Because, as CrastersBabies points out, there's a pretty hefty crowd of agents and publishers that frown on, and refuse, works with prologues.