Change Sundering so that rather than triggering randomly 20% of the time, it triggers on critical hits.
An Axe-wielding Warrior with 16 Axe Mastery does 63 damage on a critical hit against a 60AL target. They'll land a critical hit roughly 20% of the time against a stationary target of equal level. With the proposed new sundering, that damage increases to 77. Taking into account the crit-rate, that's 2.8-ish* extra damage on average.
In my opinion, Vampiric should dominate Sundering when it comes to raw damage output. The difference with this system is that Sundering has a chance to be useful as your crit-rate can be manipulated**, meaning that in certain scenarios Sundering would actually be superior to Vampiric.
*20% armour penetration would perhaps be a little too much if it triggered on critical hits.
**Striking fleeing targets, for example.
So... umm, that's pretty much it. Just a random thought to try and bring a redundant mod out of Vampiric's shadow.
