[canadjn]

You said:I have used both. When receiving a transmission that is just informational, you tend to use "Roger, Over." But, when receiving instructions or direct orders ("So-and-so, this is me; get over there and do that! Out.") you should be using "Wilco. Out."

When the guy transmitting to you said 'out' then the conversation is finished. If you then say 'wilco, out' everyone will wonder either who you are talking to or where you learned to talk on the radio.