Xaanru is correct, primary proc rate is almost twice that of secondary. Aug should be in your BoC anyways, for the following reasons.
In my opinion, you should buy a CHoS or even a SotBS... you can never have "too much agro", and the split blade does nothing for warriors besides the semi-cool blade graphic (and brutal hilt graphic...).
If you want dual wield DPS, sell your SBoD buy 2 velium gemmed longswords or maces. And then with the money leftover buy a CHoS for agro use and STILL have a good chunk of change left.
Explained best here:
TSW - Split Blade of Destruction Just my opinion though.