If I were going to switch something signficant on my bow I don't know if I would do it this late in the game. Two months might seem like a long time but depending on how much you shoot it might not be enough time to work out all the bugs.

Admittedly, I am a carbon guy. Switched years ago and see no reason to return to aluminums. Durability, penetration and speed are all better with the carbons that I have been shooting. Manufacturing tolerances are suitable enough for my tastes and my application.

As for the biscuit...I don't think you would run into a problem shooting carbons out of an aluminum sized biscuit though I know you would if it was the other way around.

Hope this helps some.