If you read the books or even just paid attention to the storyline, you'd know that Spartans are better soldiers, but ODST's have a rather arrogant attitude. In one of the books, (I believe The Fall of Reach) a group of ODSTs approaches John in the gym and threatens to beat him up. By simply defending himself, John breaks several of the ODSTs' bones. Edit: Oh, and this is all without his armor. [Edited on 03.20.2012 2:06 PM PDT]