I'd like to think acing the state certification exam means something more than passing but higher scores don't make any difference for employment, right? (Just reciprocal recognition in other states?)
As far as I know, no one sees your scores, its a pass/fail kind of thing, but some employers may have you take their own test during the interview/hiring process.
So far I've learned that EMS is something you can't really learn in the classroom -- Don't necessarily worry about a mediocre test score if you have good senior EMT/Paramedic FTO's that are willing to work with you if you're not quite confident yet.