CHDRUM, I haven't used that model Vater, but the power does not come from the stick. Your forearms can provide you with the extra power. I use Pro-Mark 11a's for all my playing whether it is jazz, rock, concert snare drum, etc. I do not switch sticks depending on the type of playing that I am doing. It is all in the technique and touch.
Good point Steve.
Just to balance this out ... a larger diameter stick is going to move more air ... making it easier to play louder. I tell my students it's like choosing the right size hammer to drive a nail. If you have a 1-penny nail you don't need to use a sledge hammer. The bigger the mass is that strikes the surface of the drumhead, the greater the area of impact, the more air is moved, the louder the drum is going to be. You can compensate with velocity ... but there ARE limits to just how loud a 11A can get. The Fusion model would be a better choice if you plan to play loud for extended periods of time. No need to burn the calories and have to play hard ... why not just use a bigger tool and work less. Try flipping the stick over, using the butt, and HEAR the difference.
FYI ... I use the butt of the stick from time to time for big back beats; great for ballads. It seems to bring out more of the body of the snare, as well as emphasize the fundamental pitch.