Blade of Tactics adds 60 attack power. 30 directly on the weapon and 30 from the worn buff. While this is likely a bug its not one that anyone likes to talk about because it is so awesome.
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The problem with dw for dps is the amount of aggro generated and the way the crippling blow mechanic works. Triple damage (crippling blows), along with triple attack, along with precision makes ToV 2h weapons superior to any dw combo. That said, when procing avatar, or not below 40% hp, or using a knight tank dw is a great set up.
As for the OP, berserk warriors care greatly about HP. Most dps fights I'll duel a rogue and get to 30% hp. When wearing all of the AOB items, ring10, etc its quite hard to stay below the berserk threshold. The more total HP one has the longer you can stay berserk.