How about Halo 1? Pistol or...pistol? They completely changed the formula from Halo 1 to the rest of the series.

As for playstyle, the 4 different mid-range weapons have nothing to do with it. They all perform roughly the same with a tweaked RoF in exchange for a tweaked damage value, etc. All that affects is personal aesthetic tastes (i.e. you hating Covenant weapons).