I wasn't disagreeing with that - I went from softer fins to leaders and noticed the change in kicking style but I don't think it's a hard change to make - it just came naturally for me, which I guess is from having a good technique.

I think if you don't have good technique, it doesn't matter how you try to use the fins. I mean, if someone who had a bad kicking style read on here they should be doing a 'fast, narrow kick' because they wear fibre fins and go to the pool and try to change their style, they'll end up looking silly and not getting the best from their fins.

Good technique is key.