Have been wearing Elite ilvl511 (upgrade 2 times) Legguards of Failing Purification, T14 Gloves of the Thousandfold Blades, T14 LFR Helmet of the Thousandfold Blades and Chestguard of Nemeses for raiding.
Today just drop a Tunic of the Thousandfold Blades +695 Mastery, and compare it to Chestguard of Nemeses +756 Mastery is it not a major upgrade.
Been to Shadowcraft, it show 4 peice give 100dps more after I replaced Legguards of Failing Purification with T14 Legguards of the Thousandfold Blades, and wearing my T14 chest than Chestguard of Nemeses.
So my question is 4 piece bonus really good?
EP values based on full BiS.
T14 2 set: Increases the damage done by your Venomous Wounds ability by 20% = 1320 EP
T14 4 set: Increases the duration of your Shadow Blades ability by 12 sec. = 1220 EP