Armor penetration is already our best PVE stat for combat builds, and with expose armor/mace spec and S7/T9 gear about power leveling, 60% armor penetration before trinket proc is not a dream. I went on TR and dueled Veex and a few other warriors with S5 gear. With just 176 armor penetration ratings, serrated blade, expose armor, and AR/prep/mace, the sustained damage was very pleasant.

Unfortunately, for mutilate power leveling, 25% of your overall damage comes from poisons, and that does not scale with armor penetration at all. It also will not do anything against abilities like soul link or 3.2 resilience flat damage reductions, making it weak vs. warlocks, probably our toughest opponent in 3.2 arenas. Blizzard chose to cap armor penetration against heavy armor. Against a warrior with 14K armor, 60% reduction would only take away 6000 instead of 8400, so unless AR/prep somehow becomes the dominant spec of 3.2, attack power stacking is still superior power leveling.

One of the most underrated talents in the game. -375 armor is a passive 2%-5% damage bonus depend on the target armor. The lower the enemy armor value, more effective this is. +30% to rupture damage is very strong against heavy armor as well, although ruptures use diminishes greatly in group PVP. You obviously need this if you are hemo about power leveling.

A much, much better talent when you can have it with cold blood. A 5CP cb evis first second into cheapshot is amazing. Still enough time to hemo and gouge and a potential 3CP kidney shot. A super fast 5 point expose armor helps too. A lot better than what people give it credit for. Hemo and Ghost Strike are not normalized and truly benefit from high AP. This is amazing synergy with +15% agility a little bit further down the tree power leveling.