I did se 1 comp long time ago that had Sub rogue Mostly PvP geared, around 4-5 PvE pieces, and a Combat Rogue partner with 6,5k PvE.
That was the nastiest damage comp I've ever seen, If I didn't HoP my Warrior partner within 2 Seconds he was dead, I had to Trinket the sap or it was a loss, Killing spree and Ambush spam from sub was the highest burst damage I ever saw in my 2k Arena games I did.
But we did counter it and after that initial burst the combat rogue was dead within seconds aswell, Combat has a hard time surviving in PvP, sub is much better all around.