Gravitational Anchor: Chance for Hold questions!

Anyone familiar with Gravitational Anchor: Chance for Hold? Trying to understand its special effect gives a "6 or 8 sec mag 2 hold", however it is being used by a power that is already a Mag 3 hold. So is it an additional chance for a hold, A chance for a 2 and a 3 on a AV/Boss as an example... a stack... now a Mag 5 when it procs or does it overwrite the mag 3 and is useless?

It is a chance for stack. So treat it as a mag 3 power with a chance at mag 5

does it overwrite the mag 3 and is useless?

Hold magnitude always stacks. That's how you overcome hold protection. Like a boss has 3 points of hold protection normally. If a controller uses their hold it's 3 points (unless they get an Overpower which is a dandom hold crit). A few seconds later when the power recharges they can hit the boss again for 6 total.

 

Petrifying Gaze was nerfed hard to make it impossible to stack without massive investment in enhancements. It used to be more spammable than a controller hold. @_@:;

One thing to keep in mind with hold procs is that they do have a fixed 8-second duration and aren't affected by enhancements. So in general if you're stacking it with a hold power the hold from the proc will wear off first.

I have decided to abandon Gravitational Anchor for my final build. I have decided its not the best choice