I have PLENTY of friends who play halo 3 and who're gonna play reach and all of em are livid that they cant have a feminine model for their avi. i for one believe that everyone should get to be what they want. also, for anyone who is complaining on the issue with NOBLE squad's Kat, she has a feminine look about her because shes from the SPARTAN-III program, with the rest of the squad (save Jeorge who happens to be a S-2). the difference between the two are S-2's are larger, more muscular, and stout. Halo 3 boasts SPARTAN-II multiplayer characters, therefore, the models are the same, the armors are the same. S-3's are a cheaper and more effective way for ONI to give the UNSC SPARTANS, are given injections of similar enhancements which give them the endurance, health and speed of an S-2 while not having to go through the arduous proccess of injection, mutation, and rehabilitation. S-2's take (dont quote me, been a while since i read the books) aprox. 3 hours for injection 8 hours for mutation, and 3 weeks for them to get used to the new body. not to mention the near decade it took to train them. the cost of armor between the types for outfitting was reduced greatly for S-3's had SPI, or semi-powered infiltration armor, that being lighter, less shielded, and more stealth-based in comparison to the tank-worn MJOLNIR.