I have thought a lot about vehicular combat.

I think that Halo 2's introduction of ally driving and weapon swapping were recipes for frustration.

I think that ally AI behaviour with respect to vehicle usage is one area where 343 could have vastly improved the game-play.

It sounds like they have made some improvements. I would need to play the game to know exactly what the changes are like.

The improvements seem to be mostly omissions:

1. charged pp shots removed/reduced
2. grunt suicide stickies removed
3. taunt enemy corpse removed
4. concussion cannon weapons that can blast hog tens of meters backwards removed
5. the weapon swapping dance removed

But I had hoped to have more control, more influence over the driver whilst manning the gun. At the very least I would have liked to be able to tell the driver to stop and start. Fast switching between seats would have been good as well. And allies should board the vehicle immediately when you board.

I think that 343 has concentrated more on the squad mechanics. I wouldn't have gone down that route as poor companion AI has blighted the later Halo games (for me). Having allies stand five feet away from you and not revive you when you call for help is criminally bad.

So Halo 5 sounds like a mixed bag to me; some improvements have been made and some opportunities for improvement missed.