Depends on the weapons you're using and how often you use the basic attacks. Dual Wield users get the most out of those enchantments because they can stack them on two weapons at once, and can use light attacks to rapidly receive the benefits.

To answer the question though, in the above example, you receive 9 magicka every time the weapon procs. And since there's no cooldown in the description, it's pretty much a guaranteed proc every time you swing and hit with the weapon. Though that also means faster charge depletion.

hmm I thought it was 3 seconds.

Legendary VR12 enchantments deal 39 Magic damage and recover 16 Health, Magicka, or Stamina.

Internal cool down is 4 seconds. A legendary weapon can have the Powered trait, which would reduce that by 50%, giving you 16/2 = 8 attribute/second and 39/2 = 20 DPS.

Natjur wrote: »

But if your not doing many basic attacks (light or heavy) then the enchantment means very little anyway.

They trigger off weapon attacks, too.

And you can "weave" light attacks in between spellcasting.