John,
The idea of carbon giving you more speed is being able to use a lighter arrow with the same spine. A lighter arrow tends to make a bow louder and does not penetrate as well. That probably won't be a problem on broadside shots at deer and on smaller animals, but lack of penetration can sure be a problem on larger animals, tougher animals like wild pigs, and shots on deer from angles that require the arrow to do more than go through ribs and lungs. I don't have a very good idea about shafts that work at shorter lengths, but some of the others here will know. You need to state the draw weight at 25" that your Big East pulls so someone will have an idea of how to spine the arrow.
Allan