Im sort of upset, yes. I much prefer elites to spartans, just because I think they look cooler. but then again, it doesnt really matter because i dont have live :-(. But there are more than just hitbox and speed differences. The most major of which is in reach, their shields and health.
Spartans: shields start regenerating after 6 seconds. Fully recover from empty in 3 seconds. Spartan health recovers in thirds( it will never regenerate more than a 'section' of 3 health blocks. Health begins to regenerate after 4 seconds and takes 5 seconds to regenerate. The first block will regenerate faster than the last 2.
Elites: shields start recharging after 4 seconds. Fully regenerate from empty in 4 seconds. Elite health takes 16 seconds to fully regenerate from 1 block. Elite health completely regenerates, eliminating the need to use medkits. The health regeneration begins quickly and ends slowly.