This is something I have been playing with the past couple days.
I also have been unhappy with the performance of my dirge, which up until this past sauturday averaged 15k with peaks at 25k dps. I have adjusted spell rotations and everything. I then consulted one of our raid dirges who is putting up numbers around 80-100K with DOV T1 and x2 gear. The best advice he gavem me was a spec change.
Str 8,4,10,1
Agi 4,4,10 (8 in Stealthy Ambush)
Sta 4,4,10
Wis 4,4,10 (8 in Swift Voices)
Int 1
Re Adorn - Every piece of White, Yellow, Red to multi-attack you can
My Dirge Stats for comparisson(self buffed w/out battly cry, my swashy owns BC)
Crit - 221
Crit Bonus - 143
potency - 127
ability mod - 576
Multi-Attack - 195
flurry - 2%
Agility - 2649
Gear - All Legendary Instance on armour side cept SF T1 boots
Blades - Zorglims Blade(x2) and Blood Drenched Dirk(crafted)
Jewels - Legendary DOV and 2 DOV x2 pieces
After the spec and adornment adjustments - avg 34k dps and spikes over 50k on the bot
played straight up averaging 45k with spikes to 60's
My Box Group is a Guardian (30-40K), Swashy (80-120k geared to the nines has hardmode gear), Coercer (15-30k work in progress), Dirge (30-40k), Templar (0k) , Fury (10-20k) Group average is about 230k in DOV instances and wish i had more