They are very close, the Tier 7 favors avoidance while Dragonbrood favor TPS. Are you low on +hit? Are you hurting in the Dodge/Parry department? Also and most important: Are you useing the T7 leggings to get your T7 2pc Set Bonus!? (which is freakin awesome)
If you are geting T7 for 2pc, use T7. If not and your hit rating is below 200, use Dragon Brood Leggings.