Worth it to keep Perfect Zinger?

I have a couple of Invuln/ tankers that have the perfect zinger proc in their invincibility from ages past, and I'm perfectly happy with their builds (Inv/SS and Inv/DM respectively), but my question is: is it worth not respeccing and keeping the damage proc slotted or would you respec and keep playing with builds? As I said, I'm happy with their current condition, but there are a few things that I could tweak to perhaps improve on their survivability.

You could always make use of the dual builds feature and see which one plays better. It's a lot more expensive because you'd essentially have to build him again from scratch, but the option is there.

That's a good point. I hadn't thought of that.

I thought they "turned off" the Proc from PZ in Invincibility a while ago. If it's in there it's not doing much good. If that's the case a respec would be a better option to recover the IO and either use the slot somewhere else, or add a common IO Taunt (of course you could just put the common IO over the PZ Proc, but then you'd lose it).

I'd also like to add that in an aura the proc will only be allowed to check every 10 seconds. If Invincibility pulses every 2 seconds it would only check every 5th pulse. IF the proc still works in Invincibility you're probably going to see it proc on about 4% of the targets in your aura +/- 1%.

The proc still works. I've also had it proc on multiple mobs simultaneously.

Interesting... Did they change the bug that was causing the self stunning? Or, am I think of a different Proc? I'll check to see if I can slot one. Last time I tried I thought it was grayed out (Not allowed).