They won’t drive through hardboard, but I’ve used them in pine up to 3/4" with success.
IIRC, the concern was that they would jam up a gun that wasn’t built for them, but I’ve never had a jam in my cheap nailer. They do shatter spectacularly when you try to drive them through something too hard, so, as always, wear your safety glasses.
They’re a little pricey compared to regular brad nails, but it’s worth it to me to not have to worry about ruining a bit or leaving remnants of a metal brad in the spoil board.