we did officer trading once - my son was probably 3 at the time and the pin he got (on older Remy / Ratatouille pin) is his absolute favorite since he got it from "the captain"
We did a couple trading events but never traded any pins b/c my impression was that others there were "professional" collectors and had tons of el cheapo pins ready to trade for our best pins. . .
So glad to know that your son had a great experience. And sorry to hear your disappointment at events.
Our family are new into pin trading and we just want to have a good time. We are not trying to complete sets nor do we have trading goals.
In preparation for this trip, we have purchased pins from Disney parks overseas to bring to trade on ship. We wanted to trade out good pins for good pins, so that everyone have a good time. I believe in the long run, we will remember these moments, not the pin itself.