Canon Fast Sharp Lens Is The Sigma Lens Autofocus Fast Enough?

Is the sigma lens autofocus fast enough? - canon fast sharp lens

I looked at the Tele-Sigma - 150-500mm 5.6-6.3 DG OS HSM. Has anyone used this lens for sports photography fast - rugby, football, athletics or airshows? Can Auto Focus "hold" per share. (Pictures sharp? Be used), is a Canon 20D. I wish I could afford genuine Canon lenses, but they are too expensive financially. Who, or have that goal in these cases? His advice, suggestions or complaints would help track!
Salud!