The single biggest flaw in Halo CE’s multiplayer for me is the movement. It was not very intuitive as far as when you were able to jump from a playform. i.e. it looked like you were still on but when pressed A it didn’t jump. Otherwise CE is the most balanced, and most fun Halo game to date.
Halo 2’s biggest flaw was superjumping. The other glitches added skill to the BR. There is no debating that. It might have destroyed the rest of the weapon balance, but it made the BR the single hardest weapon to master in any halo game.
Halo 3’s biggest flaw is without a dount the netcode. Sooooo many dropped shots.
Reaches biggest flaw is that it is not a proper Halo game.