If I may interrupt:
Voice commanding drones means you just have to tell it to do something and it'll do so as good as it can and more importantly, as far as it understands. It uses its own pilot rating (possibly together with autosofts) and is self-controlled.
AR will usually get better dicepools, but it also means you have to command everything it does with a complex action, even if it's only a simple action for the drone. Also means it does -nothing- but what you tell it to. (eg: If someone takes a swing at it with a hammer, it'll just stand and wait for the blow unless you use a complex action to tell it to dodge. A voice commanded drone will recognize the attack and try to dodge automatically.)
Main problem with voice command is the drones "dog brain". It's usually quite limited to the drone's immediate programming. A moving drone will understand "move over there" or "follow that person", it'll move around objects and find the most logical way, but if you ask it to do so quietly, it usually won't understand unless it's got Covert Ops autosoft. Same for attacking, while an autowelder drone could really hurt a person, it's unlikely to understand an order like "attack that guy", even if it has targeting software for its normal job, targeting people is something it's not programmed to. (And here, if you instead use Command in AR/VR, it will do so without problems.)
Drones with high Pilot software and/or Fuzzy Logic upgrade are a bit better at understanding things that aren't part of its normal programming.
Pretty sure that's how it works in the book... of course if Chrona rules otherwise (or if the drone has been programmed otherwise), feel free to ignore this.
EDIT: Page reference on SR4A pg 245
Three ways to control a drone:
1. Issue command (can be done verbally, drone will try to understand the order)
2. Remote Control (this is what the Command Program is for)
3. Jumping in (hyper realism dumpshock causing stuff)