I certainly share your opinion. But it is just an opinion, so I was wondering if anyone's actually given it a shot. Doesn't sound like it though... and I'm not willing to spend the respec fee to find out if it's still bugged even.
Points are tight, but empirically a few people have said that improved revenge only boosts the *built-in* damage. If that's the case that talent isn't nearly as good as we think and could be worth swapping.
I think if I could find points to shuffle out for it, I'd definitely try it. Hell taking out 2/2 gag order if I know I won't be silencing any mobs would be a great place to move it. 10% off shield slam damage is rough but math shows it'd be <2% decrease in your overall TPS. If the 10% thing works, then for sure on a boss that is disarmable, it'll increase your raids overall damage no? 10% for the raid is definitely > 10% for yourself. but the bigger question then is if it works, does the effect still work on non-disarmable bosses?