I think Sage wanted to balance the game much further than Bungie allowed.
I remember him talking about how to changed the balance of the Warthog, given his work on Shadowrun, I would have trusted every one of his balance decisions. However, the rest of the team made him change the Warthog back simply because it didn't "feel" like the old vehicle.
Look at the Beta for H:R.
The DMR and Pistol had vertical recoil in addition to bloom, and in addition to that, the vertical recoil was reduced when in scope.
The recoil actually evened out the bloom of the DMR and Pistol because you had to take the time to readjust your aim, allowing the bloom to quasi-reset while you did so.
However, this feature, which I personally really enjoyed, was taken out. Also, the Pistol was the closest thing to a utility weapon we had since Halo 1. If you were good with it, which I considered myself to be, I could play smart and engage a player wielding any weapon in the sandbox.
Some Beta Pistol evidence to back it up:
http://www.youtube.com/watch?v=-nYE6llWfcA