Here is a list of reasons why ODSTs are more bad ass than Spartans:
01)Marine Corps
02)Semper Fi
03)they don't need military grade steroids to be badasses
04)no mommy and/or daddy issues
05) orbital -blam!-ing drops! Feet first! And no fancy armor to protect them while they do it.
06) more personality than a brick. Suck it Master Chief
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ODSTs drop inside pods. Spartans drop with nothing but the armor on their backs. Also, before the augmentations, Spartans were in peak physical condition as well as incredibly intelligent due to intense training and education they underwent for years. The augmentation just served to (wait for it) augment that. They far surpass ODSTs in every category.