My idea is that its a combination of both, Free Will and Destiny depending on person to person.
From purely Spiritual point of view, Soul is most powerful, followed by Brain/Logic, followed by Mind, followed by Sense Organs and lastly Materials.
The one who has positioned itself at Soul level, nothing is impossible for that person. Which means they can fly like birds, disappear and reappear, fire can not burn them and water can not drown them etc.
But 99.9% of people work at senses and mind level and hence they have fixed tendencies depending on their likes and dislikes. These likes and dislikes greatly affect their choices and this becomes a perfect pattern often named as Destiny.
In short, sometimes we make choices and rest of the times we blindly follow our likes, dislikes, fears, beliefs, thoughts and conditioning of mind.