I have been waiting for years to see some supportive data, and it has been coming out this year. First, on ESPN Sport Science, they proved that using a weighted bat prior to a game at-bat actually decreased swing speed by as much as 5-8%. That's like physically increasing the pitchers throwing velocity by 5-8% without him doing anything!!! But now, I have some hard data in my hands from the Strength and Conditioning Journal. This data (5 different documented studies) proves my point. The use of any weighted bat greater than 10-12% of the game bat weight significantly reduces swing velocity. They have found that using a warm-up bat + or - 12% of the game bat weight produced the greatest increase in swing speed. Also, using a stick that weighed 9.6 ounces produced similar results when used in conjunction with the game bat.
Now they also noted in the study that using weighted bats for training purposes (off-season) produced increase swing speeds in the 8-10 % increase category. This was possible because of the muscular adaptation principle seen in this kind of off-season training.
Anyway, in conclusion, my recommendation is when in doubt; use a bat that is 10-12% heavier or lighter than your "gamer" while in the on deck circle.
If you want to try the 9.6 ounce bat in practice, go ahead and if it works better, take it to game day. The thing to remember is that using a real heavy bat on game day causes muscular fatigue and recruits slow twitch fiber, not the all important Fast twitch fiber.
TO GET QUICK, YOU DON'T HAVE TO CARRY A BIG STICK.