Item Set Bonuses
Item - Rogue T15 4P Bonus Shadow Blades also reduces the cost of all your abilities by 40%. 15%.
Amazing piece of fine-tuning by Blizzard. T15 bonus so powerful for combat that combat (and combat only) rogues would wear T15 over T16? TO THE GROUND.
I'm sort of afraid that they are making changes like that so late into patch development. This with the yesterday's reversal of Assassin's Resolve buff makes me afraid that when I log on patch day I'll suddenly be way weaker.
Switch to Combat (if you have a weapon for it), use Blade Flurry and Killing Machine and hope he dies.
Re-read the second half of my post, unless you know of some other cleave-like ability rogues posses I think I went nearly under 10 secs with Blade Flurry by the end of my BT farming (2nd glaive eventually dropped... over 5 years after I first killed Illidan but it's still pretty)
Heroics tends to last 10-15-20 mins these days. A LFR raid, at best, last a little less than a hour and can get up to 2 hours if you have one (very) terrible group.
This week I was short on VPs so I queued for the first time in the long time for a heroic. Got a pretty decent group. Done Strat in 6 minutes