From purely a physics and ballistics standpoint - the difference would be distance and accuracy *at a distance* if I'm understanding your question correctly.
Consider this: Higher FPS can/will typically mean that the gun will shoot straigher (less of an arc) which is again when the hopup is supposed to kick in.
All things aside, *ignoring hopup, ignoring barrel variances, etc.* the only thing generally that a faster FPS will do is reduce the arc that gravity causes which could mean more distance.
Accuracy I would think then is the equasion of how you're compensating for all of those (or how you have your weapon set up)
Last edited by enigmahack; January 21st, 2008 at 17:51..
Reason: Stalker explained faster than I could lol