Humorously enough, this is not the correct name for this item. A typo was made that stuck...
While the regular synth is Tabarzin, the HQ synth is actually called "Tarbazin+1". I saw our server's leading goldsmith sell a bunch of Tabarzins months ago, and I knew she was trying to get the HQ. When I saw this pop on the AH finally with its glaring typo, I couldn't help but be amused.
It's fantastic actually. I believe the only things that match/beat that for a 1handed weapon are Woodville's Axe, Mighty Pick on Windsdays, and Company sword if you have 2 or more people in your party.