So I'm one of those guys that always likes to do things my own way. Fully expecting that not everyone will like my play style, I hereby open myself to critique.

Here is the build I use, which I call "Thrashless Full Darkness"

I run the standard Wither/Shock to 3 stacks for a HD cast. Instead of filling it with Thrash I find in pvp that I have a lot of chances to Maul (and Maul again, and Maul some moar), Assasinate and Discharge. I use the 2 set tank bonus and apply spike to peoples' faces liberally. Along with OCSing, stiming, pulling, taunting, stunning, and overloading I don't find myself filling with SS very often and usually have enough force for whatever comes next (something I felt I was lacking trying to consistently fill with thrash). I usually stay in my tank roll and gaurd things like healers and nodes. In a fight I try to make sure that the discharge debuff, taunt and wither are up on as many as possible. I run in dps gear with a little defense (since I'm itemized to 27% crit 75% surge the rest power). I'm comfortable soloing most people when it's a clean fight and can usually take out 1 1/2 in a 1v2. My dps seems to be on par with other tank/tank-hybrids.

Thoughts/Suggestions?