Donate body to science or donate organs?

I was wondering, which is more helpful in the long run, organ donation or whole body donation to a med school? I know you can’t do both. Since I don’t plan to go any time soon, I was wondering if age makes a difference. For example, if I choose organ donation, are the organs of a 70 year old less useful than those of a 40 year old? Just looking for opinions of Dopers out there who might be considering either option or just want to chime in.