You want someone prominent yet write good stuff about you.
My view is LOR helps a lot. Besides paper stats, LOR is more personal. Anyone likes to read letters than numbers, right? Depends on how they word your weaknesses, sometimes help sometime hurt. Remember faculty have to be objective to give the most accurate view of you. But I am certain that you can bring in the best side of you when you ask for the LOR. Most professors are nice enough to write you a decent letter.
If you want a strong one, do research or work for your professor.
Get them to know you in whichever way possible.