25 all Stat is bad and far away from the description (also the bonus last 3 sec with no visual effect).
A 250 all buff should be appropriate, if this proc will be in combo with the full set and high primary awaken it can jump to 500+ on primary.
The result will be 250% more bonus dmg provided by primary increase and more consistance for the character stats.

Keep in mind that ebon armor gives 200% more dmg and a 20-25% haste so actually op. (And it's a 71 item)
And the legendary set 6/6 and 3/3 bonus stacks, so this full set provide 50% primary right now, and that s way higher that the 35% of myth set.

Maybe a buff or a rework should be considered?
And should the set be turned into yellow rarity now instead of orange and work only in underwater dungeon only?

This feature allows players to choose items based on their need,
because arcane items will always provide best stats for each category but the full set will be the best option limited on a specific area.
I don't like the idea of change this mechanic now because it works really well.
Positive suggest below.