For those of you who play a lot of Halo 2 Multiplayer, you'll find this interesting statement on Shadowpanther.net:

Q: In multiplayer, does the Elite character model have any advantages or disadvantages compared to the Master Chief model? A: Yes. Although the Elite deals and receives the same amount of damage with all weapons as the Master Chief, they have differing melee attack speeds. In the case of most weapons, the Master Chief has an equal or slightly faster melee attack speed. However the Elite model can melee attack faster with the Brute shot (0.7) and the Sentinel Beam (1.0). The Master Chief can attack significantly faster with the Plasma Rifle, Brute Plasma Rifle, Shotgun and Needler, attacking 0.4 seconds faster with the former two and 0.3 seconds faster with the latter two.

I had no idea - I thought the two character models were identical.  Bear in mind that it is only this person's observation and not a hard fact from Bungie.  

This statement came from Halo 2 weapons spec and weapons ranking charts:

http://shadowpanther.net/halo2weapons.htm
http://shadowpanther.net/halo2rankings.htm