Will Stormraiders Fail as a Keystone?

Stormraiders is barely used now. It will be receiving some buffs in the near future though. You can check it out on the PBE here:

http://www.surrenderat20.net/p/current-pbe-balance-changes.html

But the question is will this Keystone ever be a viable pick without being brokenly strong? Assassins won't really take this mastery because they care more about actually dealing damage and securing their kill In which case they swill take Thunderlords Decree. Other champions will still prefer having the guaranteed damage over the non-guaranteed movement speed.

Stormraiders seems like a really cool concept for a Keystone Mastery as it will help to fit a certain play style. But is it that as long as Keystones remain as a one-pick choice deal that it will simply be overshadowed by a damage-focused keystone unless Stormraiders is strictly stronger than it? Or does the cunning tree simply not provide enough to adequately suit this Keystone?