I n the other end of the spectrum formula boards are fantastic for older and hardened windsurfers who still have the strengths but who perhaps have lost some of their agility and the thrill by always sailing on the border of their ability

Could you correct the punctuation please?
I n the other end of the spectrum formula boards are fantastic for older and "hardened" windsurfers, who still have the strengths - but who perhaps have lost some of their agility and the thrill by always sailing on the border of their ability.