agesilaus wrote:
Well a six point would be in contact all the way around the plastic hex. A 12 point would only touch at 12 points around the circumference. Might be a minor point.
Not quite. You are correct about the six point, but the 12 point still only touches at 6 points because that's all a hex has, the difference being that the 12 point socket only grabs the fastener at the corners. Still, if it;s gonna snap off it doesn't matter how the wrench is on there.

A 12pt socket will tend to round the corners on a stubborn fastener where the 6pt has better grip.