DO students tend to be older, a tad lower on MCAT/GPA, and somewhat skewed towards GP.
There really isn't that much of difference (unless we talk about the elite schools (Harvard, etc) which are all MDs) but to say there is absolutely no difference is a bit of.....defensive thinking.
edit: Didn't read the title completely. Insurance companies charge the same amount for DO and MDs; an arm and a leg.