An advantage to using buttons there is that the press could trigger an appropriate bit of voicing, using your character's voice. Whereas, if you've already issued a voice command yourself, it wouldn't be right to then get your character's voice as well.

: If someone didn't want to speak to the marines then he'd still have the usual
: post h2 hog using experience.

Well anyway, when I thought about the possibility of using a headset, I reconsidered my blanket dismissal of voice commands, as you may've seen in my reply to cheapLEY.

: Maybe if you whack the first marine who offers to drive then his chums get
: the message. Or you could kill your fellow marines like wot we had to do
: in post h2 games if we wanted the vehicle to ourselves. But that's a bit
: psychopathic

That's no good for me (not for serious play anyway), as it breaks the realism too badly.