The standard shouldn't be "no worse than Bush." It should be which of the two will be the better CIC. Pretty easy decision for me. Just look at the crucial decision regarding the surge. McCain was on one of the few who supported it. Some said his presidential candidacy would live or die based on the surge's success.
Obama, on the other hand, not only said the surge wouldn't work, he said it would increase violence. I don't think the man should be anywhere near control of the armed forces.
I wouldn't even trust Obama with a video game pertaining to war.