His larger canon crippled and only crippled non-shielded, sedentary Klingon vessels, by surprise.
Not only had Anakin's skills increased considerably, but his personal Force reservoir doubled, his telekinesis was far more powerful, Dooku was a weak old man by comparison.
Anakin was stated to have prescient capabilities in combat, Khan was not. He also demonstrated, all things considered, the ability to close the gap and disarm Khan before he pulls the trigger. That's if he doesn't crumple his weapon beforehand with TK, or send projectiles heavy enough to take the super soldier's head off whilst ducking for cover with speed and acrobatics that dwarf his as well.
If you want to take OT into the equation Vader can read Khan's thoughts during combat on top of seeing things before they happen. You gravely underestimate "whiney Ani".
lol, any further argument is pretty moot, null and void, most of the Klingons were able to find cover, despite Khan's obvious advantage of surprise, prep time, and the biggest fricken pair of canons we've seen in the films thus far. Under a fairer versus setting, he doesn't have a prayer of tagging Vader what with his superior speed, reaction times, agility, and telekinetic capabilities to any character in Abram's series.