Char X is a great wall breaker with access to Sword Dance and Dragon Dance. With his speedstat of 100 he speedties with Salamence and gets outsped by Garchomp by 2 points.
With 130 in SAtk and Atk it even can go mixed! With his unique typing in OU it has a great set of resistances and easy to cover weakness and a great immunity to Will O Wisp.
Talonflame has Gale Wings Swords Dance and an amazing speed stat of 126. With a Life Orb Boosted Brave Bird it takes apart teams if you are not prepared for it. Too bad it is countered quick by Rotom, something Char X isn't
So I would go with Char X