Every gun in Halo has a specific use and not over powered like in Call of Duty. When I say overpowered, I mean unfairly over-powerd. Yes, yes they're overpowered weapons in Halo BUT they are placed in specific spots on a map.. You have to utilise a strategy called 'Map Control' to get them... And you have to roughly know how to use them.. For example The Rocket Launcher has blast radius but that can be misleading as if an opponent jumps he could be just on teh line of that radius which propels him further but does not kill him.. To overcome this try to get the guy on his way down from a jump.
In call of duty you have start of with OP weapons and perks like the NoobTube, Double Model 1887 Shotguns, Commando Perk, Riot shield, Quick scoping sniper (not actually intended use) etc.
Cod - People say more guns. Bad reason because it makes the game unbalanced.
Halo starts you off with the same weapons...Ergo everyone is on equal footing. It's how you use those weapons is how you succeed. It's about about skill, strategy &(sometimes teamwork).
Plus in Halo nearly all your kills are from your weapon (True FPS style) not having the computer do it for you (attack dogs, pave low).
What I like in halo is that whenever you die your enemy actually deserves the kill. Cod's OP weapons & kill-streaks, spawn trappers, spawn kills, drop shots, or some squeaker with a sniper quick scoping everybody. I don't really consider any of these things fair kills and they are the only things that ever kill me.
Cod - A game where you camp with a knife (easy kill) to get a kill-streaks just so you can get more easy (non-player kills) with Pave Low, Attack dogs etc. (Done by the computer not by the player) and LAG is a major influence to determine many gun fights.
Take a look at this:
Point-streaks vs Kill-streaks (Middle to end of video):