When to use Stormraider's Surge

It's good on champions who can get in easily, but have trouble getting out.

Give it a shot on Wukong. He should have more than enough burst to proc it on soft targets.

Custom-made for Talon.

It's supposed to be for champions who have good burst but have trouble getting out of a fight; Talon comes to mind, I think it's pretty effective on Wukong (especially so he moves faster during his ult). I know Faker uses it on some assassins, but probably because Faker is more aware of his damage output that he doesn't need the extra burst of TL.

It might also be useful on champions who can chunk someone a decent amount up-front, but the sticking power is more beneficial than a bit of extra burst. Juggernauts such as Garen/Darius might be able to do enough with their initial combo, although I don't know if another mastery (grasp of undying perhaps) is preferable. It might work on champions like Xin Zhao or Nocturne