With a correctly placed shot, there is no difference, both are 100% effective.

As far as which is a better hunting arrow, it comes down to personal preference. Which is better Ford or Chevy, Coke or Pepsi, PC or Apple......you get my drift.

My personal opinion I started shooting carbons when I picked up archery. I guess the driving factor was more related to the fact that generally carbons are easier to maintain than aluminum arrows. In this I mean that carbons are generally good or they are broken. There is not too much in between the extremes. Aluminums can get bent slightly and present accuracy problems if they are not properly staightened. As a beginning archer, I did not want to contend with anything effecting my accuracy other than me (that was a big enough problem in itself)

That being said, many....many people shoot aluminum arrows quite effectively every year.