Another great article, Cristóbal! I think free will is an illusion, but a very useful one. Our actions result from too many events in our brains for us to be aware of all of them; so we believe we are making free choices, and in conscious effect we are. Sometimes we may even toss a coin to make a decision.
When I play chess, I feel free to choose each move, though I know my brain is making it for me based on my experience with chess. Or, after long deliberation, I may just think "Oh hell ... " and make a random choice between plausible moves.