NOTE: VBO's works great for some video cards. But in my own case it made loading the world deathly slow.
How slow? Whenn I start a world or go through a portal and the game will give ne that brown 'dirt' screen for 30 sec to a minute before coming back.
That is long enough to drown, get killed by a mob, or shot by a gast, before I can even see or do anything.