If the latest data mining is true, they even took out the 5 sec waiting time, which means basically every 30 secs you can cast on the move for 5 secs. Which definitely would make them better. As far as I know at the moment the boots are the only legendary where you have to make a macro to not profit from their trait, which is kind of sad, even for the sometimes lackluster Legion-legendaries.
We'll know more soon.
Sephuz is pretty sweet on my frost mage. Will be even better when the patch hits. CC, Interrupts AND spellsteal will set it off.