Ven's speed means nothing. Larxene was the fastest Organization member and she lost to Sora. Come to think of it, Larxene and Ven are probably at the same level, so that would be a more even fight. But yeah, Sora's more skilled than Ven, plus Sora's reaction commands would just completely outclass Ven's skill-set. So...
But, seriously, Sora would win. --- Official Luxord of the Kingdom Hearts: Birth By Sleep Board
they are all connected one way or the other roxas is sora, and sora gave ventus his haert, sort of, and roxas has vens heart. so all in all they are fighting them selves --- if i don't know something about kingdom hearts, IT'S NOT TRUE!!!
Unfortunately, Sora is leagues above what we've seen of him. However, after he's made his return who knows the heights he'll reach.
So as of now, Sora. In the future, however, who knows? The main character doesn't necessarily have to be able to beat all of his companions, or even be the strongest, so it's not like he doesn't have a chance.
I would place Ven and KH1 Sora on the same level more or less. CoM and KH2 Sora are stronger. Of course if Ven awakens with all for Roxas' powers and experience then that's a different story. --- "There is nothing either good or evil, but thinking makes it so"