I can honestly say that any experience I had with [the previous] iPhone 4 Voice Commands were purely accidental. Comparing iPhone 4 Voice Commands to Voice Actions for Android? Android wins no contest. Compare Voice Actions (Android) to Siri (iPhone 4S)?
Let’s just say that the moment an iPhone user triggers Siri, they need only speak while Android requires certain keywords in order to perform an action like “send text to” or “send email to”. Interacting with Siri comes naturally.
As Siri continues to mature and grow through the initial beta period, I can’t even begin to imagine how much the system will improve.