Women following in 4" stilettos. Personally, I do what feels natural at the time. Off the top of my head, I think when I step forward in close embrace, I'm more likely to step on the toe. When I'm led into something in open embrace, such as forward ochos, I think I'm more likely to take the heel. But I never know if one or the other is correct.
What I want as a leader: If I ask you to step forward I want you to drive the movement, to energize the step, to own it. What ever allows you to do that is fine by me.
As a follower: I have been told my heel steps are "stronger" and my toe steps are "smoother". My teacher told me she liked my follower front step better with a heel step.