Military tribunals are designed for use in wartime--in a declared war against another power--and are comprised of a governing body of military officers who have an inquisitional role and function as judge and jury. Now, I can see the value of this on the battlefield when prisoners are caught and are known to have committed some war crime or extremely heinous act of war. However, terrorism is not the function of a declared war between two powers.
A military tribunal, by definition and by Constitutional principle, can have no power or jurisdiction over terrorist acts that occur outside of a declared war. The very nature of terrorism--again, by definition--is random, para-authorized acts of violence against an enemy in an extramilitary environment and setting and milieu. Therefore it seems clear that logic and Constitutional principle dictate trial by civil court. Opinion may differ, but it is true that often times opinion has no fact backing it up, as we saw with several Congressional opinion driven decisions following 9-11.