first of: don't expect anything. i know myself pretty well, and i am fucking abysmal at fulfilling people's expectations. i'm great at procrastination and everyone should know it.
but if you're willing to take the risk =) andif it's not a huge hassle (as posters usually are), i'd rather work on top of clear 1200dpi rasters and outlines. the outlines are often printed separately, in which case they'll look way better that way.